Environmental hygiene: types of pests and pest control methods
Pests such as cockroaches, flies, rats and stored-grain insects spread disease and spoil food. Control them by denying food, water, shelter and entry, then by physical and chemical methods.
Common pests in food service
| Pest | Harm | Signs |
|---|---|---|
| Cockroaches | Carry bacteria such as Salmonella on legs and body; droppings and odour spoil food | Pepper-like droppings, egg cases, musty smell; seen at night |
| Houseflies | Breed in garbage and filth; spread diarrhoea, typhoid and cholera germs through legs, vomit drops and droppings | Flies around bins and food |
| Ants | Contaminate sugar, sweets and syrups | Trails to food |
| Rats and mice | Urine and droppings spread leptospirosis and salmonellosis; gnaw sacks, wires and pipes | Droppings, gnaw marks, grease smears, burrows, torn sacks |
| Stored-grain insects | Rice weevil, red flour beetle, khapra beetle, lesser grain borer and pulse beetle damage cereals and pulses; moths spin webs | Holes in grains, powder, webbing, live insects |
| Birds | Pigeons, crows and sparrows drop feathers and droppings | Droppings, nests |
| Lizards, stray cats and dogs | Contaminate food and surfaces | Droppings, animals in food areas |
Prevention: deny food, water, shelter and entry
- Proofing: screens on windows and vents, self-closing doors, strip or air curtains, sealed cracks and gaps around pipes, gratings on drains.
- Good housekeeping: clean as you go; no food scraps left overnight; clean under and behind equipment.
- Proper storage: food in sealed bins, off the floor and away from walls; FIFO; inspect deliveries for pests.
- Garbage control: covered bins, emptied daily; clean bin area.
- No standing water: fix leaks; keep floors dry.
- Regular inspection for signs of pests, with a pest-control log.
Pest control methods
| Method | Examples |
|---|---|
| Physical (mechanical) | Rat traps and glue boards, electric fly killers, fly screens, sieving and sun-drying of grains |
| Chemical | Gel baits and sprays for cockroaches, rodenticide baits in tamper-proof stations, fumigation of grain stores, by licensed operators only |
| Biological | Natural enemies or microbial agents; used mainly on farms and in warehouses |
| Traditional (stores) | Dried neem leaves in grain bins, sunning grains, airtight storage |
| Integrated pest management (IPM) | Prevention and monitoring first; the least harmful control; chemicals only when needed |
Safety rules with pesticides
- Only trained or licensed operators apply pesticides, following the label.
- Remove or cover food and utensils before treatment; clean surfaces afterwards.
- Never keep pesticides in the kitchen or in food containers; store them locked and labelled.
- Use bait stations, not loose poison; record what was used, where and when.
A hostel or hospital store that keeps grains in sealed bins on raised racks, screens its windows and keeps a pest-control log avoids both disease and the loss of costly rice and dal to weevils and rats.
2 marks: “Name two stored-grain pests.” Rice weevil and red flour beetle (also khapra beetle, lesser grain borer, pulse beetle).
5 marks: “How can pests be prevented from entering a food service unit?” Proofing (screens, self-closing doors, sealed gaps, drain gratings), housekeeping, sealed storage off the floor, covered garbage removed daily, no standing water, regular inspection.
10 marks: “Describe the types of pests found in food service units and the methods of pest control.” Table of pests with harm and signs; prevention by denying food, water, shelter and entry; physical, chemical, biological and traditional methods; IPM; pesticide safety.
Pests need F-W-S-E: Food, Water, Shelter, Entry. Take these away first; poison comes last, by experts.