How to get rid of cockroaches in restaurants

For restaurant owners and managers, the sight of a cockroach scurrying across the floor is more than unpleasant; it serves as a major warning sign of potential trouble. Cockroaches pose a significant threat to a restaurant's reputation, compliance with health and food safety standards and, ultimately, its bottom line. They can spread harmful pathogens and allergens, contaminate food and give customers negative experiences. Harbouring these unwelcome pests can result in serious consequences, including significant fines and even closure of the restaurant.

Controlling cockroaches in a restaurant environment presents a unique and persistent challenge. Their resilient nature, rapid breeding cycles and ability to hide in the smallest cracks and crevices make them difficult to eradicate.

Understanding their biology and behaviour, along with implementing integrated pest management principles (IPM), is crucial for maintaining a clean, safe, and successful food service establishment. This article describes practical steps to effectively prevent and tackle a cockroach infestation, protect your business, and ensure a pest-free environment for your staff and patrons. This article covers:

Sources of cockroach infestations
Cockroach identification
Restaurant sanitation practices
How to monitor for cockroaches
Cockroach control methods
Follow-up and evaluation

Sources of cockroach infestations

Restaurants offer the three conditions that cockroaches need to survive: food, water and shelter. Cockroaches can infest restaurants through various pathways, exploiting any weak points and the favourable conditions that restaurants can provide. Understanding how cockroaches access these resources in a restaurant environment is crucial to preventing and managing infestations.

External sources

Incoming supplies and deliveries

This is a very common way for cockroaches to gain access. German cockroaches, in particular, are effective "hitchhikers". They can hide within and on incoming supplies, including packing materials, cardboard boxes and pallets. Even items brought in by employees, such as on their personal belongings, could potentially introduce cockroaches.

Structural openings

Cockroaches can squeeze through surprisingly small spaces. Adult German cockroaches can hide in a crack as narrow as 1/16 inch (1.6 mm). They can also enter through cracks and crevices in walls, floors, and around doors and windows. Openings around pipes, conduits, utility lines and exhaust vents also provide potential access points.

Plumbing and drainage systems

Cockroaches can navigate through plumbing systems, using drain and sewer pipes to move between buildings and gain entry. If not properly managed, floor drains and sewer connections can provide a continuous pathway into the restaurant. American cockroaches are particularly known to climb up floor drains and sewer pipes.

Migration from outdoor populations

Certain cockroach species, such as American, Oriental, brown-banded, smoky brown, and Turkestan cockroaches, can survive and thrive outdoors in warmer climates or seasons. These species may forage for food or water, or seek shelter nearby and subsequently enter the restaurant.

Conducive conditions around the building, such as dense vegetation like ivy, woodpiles, leaf litter, compost piles, potted plants and storm drains can provide harbourage for these outdoor cockroaches, increasing the likelihood of them finding their way inside.

Internal factors

Food sources

Cockroaches feed on a wide range of organic matter. Even tiny amounts of crumbs, grease, or food residue can sustain them. Specific examples include residues on processing equipment or floors, light organic build-up, spilled food, pet food left out, unwashed dishes, and garbage. In restaurants, decaying vegetables and meat odours can attract flies, indicating unsanitary conditions that can also attract cockroaches.

Some species, like brown banded cockroaches, prefer starchy foods such as the glue on stamps and envelopes. Cockroaches in hiding places may also feed on rodent and bird droppings and animal carcasses.

Water and moisture

Water is crucial for cockroach survival. German cockroaches can live less than two weeks without it, even with abundant food. Sources of moisture include leaky pipes and plumbing fixtures, condensation, water left in sinks or bathtubs, pet water dishes, overwatered indoor plants, and unrinsed glasses or cans. High humidity can also provide sufficient moisture.

Different cockroach species prefer different moisture levels: Oriental cockroaches favour cool, dark, damp places, while American cockroaches prefer warm and humid environments, and German cockroaches prefer warm (70–75°F), humid areas. Brown-banded cockroaches prefer temperatures around 80°F. Temperatures between 59–84 °F are generally optimal for their reproduction.

Shelter and harbourage

Cockroaches prefer dark, warm, and undisturbed places, especially narrow spaces where surfaces touch them on both sides. They hide in cracks and crevices in walls, floors, and furniture, under appliances (refrigerators, stoves), behind paintings, in hollow parts of furniture, and within accumulations of clutter such as newspapers, magazines, bags, boxes and cloths.

Other common harbourage sites include voids, sewers, drains, steam tunnels, water meter boxes, areas around food waste containers, hollow walls.

Even small gaps or holes leading to voids can be prime harbourage areas, as adult cockroaches can fit into cracks as narrow as 1/16 inch (1.6mm). In restaurants, hot spots include leaky pipes, piles of paperboard cartons, sagging spots in storage areas, storage drawers with food debris, and areas under sinks or inside cooking equipment.

Cockroaches are cryptic and primarily nocturnal insects. They prefer darkness and often only come into the light when necessary due to overpopulation or to find food.

How to prevent cockroach infestation with IPM

Applying Integrated Pest Management (IPM) is the best way to control cockroaches in a restaurant. IPM provides a comprehensive strategy that combines a range of methods, as pesticides alone will not solve the problem. IPM focuses on understanding the pest's biology and habits to implement the safest and most effective control measures, focusing on prevention as the prime means of control.

Here's a detailed breakdown of how a restaurant can apply IPM to manage cockroaches.

Cockroach identification

The first crucial step in an IPM program is to correctly identify the species of cockroach present. Different cockroach species have varying behaviours, habitat preferences, and responses to control methods. The most common cockroach species worldwide that infest restaurants are:

German cockroach (Blatella germanica): This is the most common and serious in food facilities. It favours warm (70–75°F/ 21–24°C), moist areas near food and water, such as kitchens and bathrooms. It is about ½ inches (13 mm) long, light brown with two dark stripes behind its head, and reproduces rapidly.

American cockroach (Periplaneta americana): This is the largest cockroach encountered indoors. It is about 2 inches (5 cm) long, reddish-brown, and has pale yellow bands behind its head. It prefers warm (82°F/ 28°C), humid environments like basements and drains. It often crawls up floor drains and sewer pipes, which increases the transmission risk of dangerous pathogens.

Brown-banded cockroach (Supella longipalpa): This cockroach is smaller than American cockroaches, at ½ inches (10–14 mm), and light to dark brown with light-coloured bands on its abdomen. It prefers warmer temperatures (around 80°F/ 27°C) and is found in crevices near electrical appliances, furniture, and clutter, not exclusively in food preparation areas.

Oriental cockroach (Blatta orientalis): Intermediate in size (about 1¼ inches), glossy dark brown or black. It prefers cool, dark, and damp places such as basements and drains.

Restaurant sanitation practices

restaurant employee cleaning equipment or surfaces

The most effective means of preventing cockroaches is to eliminate food, water and shelter using the following sanitation practices.

1. Reduce food sources

Store all food, including pet food, in insect-proof containers with tight-fitting lids, such as glass jars or resealable plastic containers.
Keep waste in containers with tight-fitting lids and use plastic liners when possible. Empty indoor garbage containers daily and wash them regularly.
Keep waste bins clean and as far away from the kitchen or food handling areas as possible.
Remove trash, newspapers, magazines, piles of paper bags, rags, boxes, and other items that cockroaches can feed on.
Clean up all spills and crumbs immediately. Vacuum regularly, paying special attention to cracks and crevices. Use a vacuum with a HEPA filter to reduce the spread of cockroach allergens.
Wash dishes promptly and do not leave them in the sink overnight.
Eliminate grease residues on range hoods, under the stovetop, and on the sides of stoves and refrigerators.
Frequently empty sink strainers and prevent food build-up in drains. Clean drains and drain openings regularly and use covers designed to trap debris.
Regularly sweep and mop floors to remove food residues and grease. Clean food storage areas and shelves regularly.
Rinse out cans, bottles, and plastic packaging before discarding them.

2. Eliminate water and moisture sources

Eliminate plumbing leaks and other sources of moisture by tightening loose pipes, patching leaks, and replacing worn washers. Check outdoor water spigots and sprinklers for drips and leaks.
Increase ventilation where condensation is a problem. Wipe dry condensation under the refrigerator frequently and consider placing a pan underneath to collect water, emptying it regularly. Insulate pipes where condensation occurs.
Dry out sinks after use.
Empty pet water dishes at night. Ensure aquariums have tight-fitting lids or screens.
Do not over-water indoor plants.
Rinse and invert cups and glasses to dry immediately after use and dispose of drinks cans in trash containers.
Eliminate places where water collects outdoors, such as in tyres, discarded cans or tree holes.

3. Exclusion and removal of hiding places

Seal structural gaps: Conduct regular inspections of the building's exterior and interior to identify and seal all cracks, crevices, and openings that cockroaches can use to enter or harbour in. This includes gaps around pipes, wiring, windows, doors, foundations, expansion joints, tiles and flooring. Use appropriate materials like silicone caulk, expanding foam, and steel wool.
Install and maintain door and window hardware: Ensure doors and windows fit tightly and install or repair weather stripping and door sweeps. Keep unscreened windows and doors closed. Consider using air curtains at doorways, especially loading docks.
Screening: Install fine-mesh screens on all windows, vents, and other openings to the outside. Repair any tears or damage promptly.
Check appliances and furniture: Look for egg cases glued to undersides and backs of furniture, in refrigerator and other appliance motors, boxes and other items, and remove any found.
Plumbing integrity: Maintain plumbing in good repair to prevent leaks, which provide essential moisture for cockroaches. Regularly inspect and repair leaky taps, pipes and fixtures. Ensure proper drainage and eliminate standing water. Keep drain traps filled by periodically running water in infrequently used sinks and drains.
Incoming goods inspection: Implement a thorough inspection process for all incoming deliveries, including food, beverages, and supplies. Check packaging, especially cardboard boxes and pallets, for any signs of cockroaches or their egg cases. Consider having suppliers switch to less susceptible packaging like plastic.
Educate employees: Educate employees how to prevent the introduction of cockroaches on their own belongings, to recognise signs of cockroaches and to report any sightings.
Landscaping management: Maintain the landscaping around the restaurant to reduce potential harbourage for outdoor cockroach species. Trim shrubs and trees away from the building foundation. Remove leaf litter, mulch and wood piles that can provide shelter. Ensure proper drainage in the surrounding areas. Consider a gravel perimeter around the foundation to reduce moisture and harbourage.

By consistently implementing these proactive measures, you can significantly reduce the likelihood of cockroach infestations by eliminating their essential resources and preventing their entry into buildings.

How to monitor cockroaches

Regular monitoring is essential to detect cockroach populations, identify heavily infested areas, and evaluate the effectiveness of control efforts.

a person inspecting restaurant counters etc with a torch, or cockroach ootheca, or cockroach-damaged packaging

Visual inspections: Use a torch to inspect cracks, underneath counters, around water heaters, and in other dark locations where cockroaches may hide during the day. A small mirror on a long handle can be useful in hard-to-see areas. These are the signs of cockroaches:
- Sightings of live cockroaches, adults or nymphs, particularly at night when they are most active.
- Cockroach body parts, such as legs or antennae.
- Egg casings (ootheca), which are small, purse-like structures that contain cockroach eggs. These may be found in dark, sheltered places where females deposit them.
- Cast skins (exuviae), which are the exoskeletons that cockroaches shed as they grow.
- Small, dark faecal spots that resemble coffee grounds or black dust. These are found on surfaces where cockroaches congregate or travel, such as along walls, in cracks, and in harbourage areas, including inside cupboards and equipment.
- An unpleasant, intense, musty odour that is characteristic of cockroach infestations.
- Damaged food packaging, as cockroaches may feed on the contents or the packaging itself.
Placement of traps: Sticky traps or glue boards are used as monitoring tools.
- Place traps in several locations, especially at the junctions of floors and walls and close to suspected sites such as behind appliances, in cabinets, under sinks, and near sources of heat, water, or food. In the kitchen, put traps against walls behind large appliances and in cabinets. Place traps in all corners of the room to understand entry points.
- Number the traps to keep records for each separately.
- Discard old sticky traps by placing them in a sealed plastic bag in the waste bin.
Regular inspection schedule: Establish a routine schedule for checking and replacing traps, ideally daily or at least a few times per week initially. Record the number and location of cockroaches captured on each trap. This data will help identify "hot spots" of activity and track population trends over time.
Employee reporting: Encourage and train employees to report any cockroach sightings immediately, along with the date, time, and location. Implement a simple system for reporting this information.

Control methods

An IPM approach prioritizes non-chemical methods first. If chemical pesticides are needed, they should be used in a targeted manner using products posing the least risk. Special care should be taken to prevent contamination of food, packaging, equipment, utensils and around the restaurant.

Non-chemical methods

Trapping: Sticky traps can also help reduce cockroach numbers, especially in localized areas. Baited jar traps are another non-chemical option.
Physical removal: Use a vacuum cleaner with a hose attachment to flush cockroaches out of hiding and vacuum them up. Ensure the vacuum has a HEPA filter if needed. Dispose of the vacuum bag properly.
Heat treatment: For severe infestations, professional heat treatment involves heating the infested room or rooms to 140–150°F for several hours to kill the cockroaches and their eggs.
Insect growth regulators (IGRs): These compounds disrupt the normal growth and development of cockroaches, preventing nymphs from maturing and reproducing. They are considered low in toxicity to mammals.

Chemical control

person applying cockroach bait, dust, or gel bait

Insecticides are most effective when combined with sanitation and exclusion. Remember, pesticides alone will not solve the problem and it is best to get professional help when using insecticides in a restaurant environment.

Factors to consider before using pesticides include the infestation level, cockroach species, location and regulations.

Baits: Bait products (gels, pastes, granules, bait stations) are primary pesticides used for cockroach infestations. They contain an insecticide mixed with an attractive food source. Place baits near hiding spaces or where cockroaches are likely to encounter them while foraging, such as under appliances, along walls, and in cabinets. Baits can be very effective for long-term control. Consider using different bait formulations and active ingredients, as cockroaches can develop resistance or aversion to certain baits.
Dusts and powders: Insecticidal dusts like boric acid and desiccant dusts (diatomaceous earth, silica aerogel) can be applied in enclosed, out-of-the-way locations where cockroaches hide, such as wall voids, behind switches, and along wall edges and cracks. Boric acid is a contact and oral insecticide providing long-term control if kept dry. Desiccant dusts cause dehydration and should be applied lightly to avoid repellency. Boric acid is not recommended for outdoor use as it can be toxic to plants.
Crack and crevice treatments with gel baits: Gel baits are very effective when applied in small dabs in cracks and crevices where cockroaches harbour or forage.
Avoid foggers, sprays and aerosols: These are often ineffective as they don't reach places where cockroaches harbour and can cause them to disperse, leading them to return later. They also pose concerns of exposure to toxic substances. Cockroaches can also become resistant to insecticides in common sprays and they should not be necessary if an IPM program is followed properly.

Continuous follow-up and evaluation

After implementing control measures, it's crucial to regularly evaluate their effectiveness through continued monitoring and adapt them accordingly.

Regular monitoring: Continue the monitoring program with sticky traps and visual inspections to assess the effectiveness of control measures and detect any resurgence in cockroach activity.
Record keeping: Maintain detailed records of monitoring data, control measures implemented and cockroach sightings. This information is essential for tracking progress and identifying trends.
Data analysis and strategy adjustment: Regularly review the collected data to evaluate the success of the IPM program. If cockroach populations are not being adequately controlled, re-examine the methods used and adjust the IPM strategy as needed. Look for other sources of infestation, ensure all entryways are blocked and confirm food and water sources are minimized. Consider moving bait stations, using more stations, applying more bait, or trying a different bait product.
Staff Training Updates: Regularly update staff training on sanitation protocols, exclusion practices, and reporting procedures to ensure everyone is contributing to the IPM effort.

Professional pest control

For serious indoor infestations or complex cockroach problems, engaging professional pest control services [add link ] is often required. When choosing a company, ensure it meets legal requirements, including proper certification and licensing, and ask for local references. A professional can provide expert identification of the pests, develop a tailored IPM plan, and apply products that may not be available to the general public.

Conclusion

By consistently applying IPM principles, using a proactive approach focused on prevention, and maintaining an ongoing monitoring and maintenance program, a restaurant can achieve effective and long-term cockroach control. This will reduce the reliance on pesticides and create a healthier and safer environment for staff and customers.