Raphael Kimari, nailing a piece of an iron sheet to a macadamia tree at his farm at Githakwa Village in Tetu, Nyeri, in a bid to deter an invasive from squirrels. [Kibata Kihu, Standard]

Wild birds and small mammals are known to spread many diseases including Avian influenza, fowl typhoid, fowl cholera and coryza, they must be excluded from any poultry unit.

Wild birds and rodents must not have access to poultry houses, the barns must have secure wired sides or be fully enclosed. To control rats and mice we recommend a strict Rodent Control Program using an industry-related product all year round.

These prevention control programs can be either through service contracts or under farm staff control. The most common rats are the roof rats and the Norway rat. To distinguish the two, the roof rat has a long tail if bent can reach the tip of the nose while the Norway rat has a shorter tail.

Why do we need to identify the species of rats?

Rats differ in their lifestyles, while most are nocturnal; some are more active during the day. Some like to burrow while others prefer staying on the rooftops. We need to know these behaviours to help us take the poison to the rat, it saves time and money.

Rats generally have poor eyesight and therefore prefer performing their activities at night. They rely heavily on smell, touch, taste, and hearing to locate their surroundings, find food, mate and look for shelter. They are considered colour-blind and respond to degrees of lightness and darkness in finding their way around.


Rats move around in search of food, water, and shelter and during mating season in search of a partner, they can cover up to 500 meters in one night alone. This is how rats cause menace in a poultry house:

Rats have got a strong pair of incisors on both the lower and upper mandibles. These teeth are so strong that they can chew wood, plastic, and metals.

They can destroy piping in the flock units, feeders, nest boxes, etc. besides eating chicken feed. Brown rats are known to exert a gnawing power of 500 kg/cm2 using their incisors. They are agile and excellent climbers.


A female rat can produce up to 12 pups at birth and breed 17 times per year thereby producing about 200 offspring per female in an ideal situation. On average one female will produce 120 pups per annum. It takes one pup 21 days to mature. Their population growth is phenomenal.

Rodent control strategies.

This should be done in feed mills/factories, poultry units, hatcheries, households, granary stores, etc., we should not allow rats at all in any premises because, besides causing damage, they transmit diseases to both human beings and poultry. The baits should be placed in a baiting station, box, or inside a 12-inch-long and 4-inch-wide waste pipe along the perimeter fences, along and on the outside of chicken houses. Baits should not be accessed by wild birds, dogs, cats, monkeys and should be securely and safely positioned. Keep baits away from children.


It is important to first assess the area you want to place your rat bait or trap. You should try to eliminate or minimize the abundance of rodent food sources such as garbage cans, and open containers of food.

Given the option, rats will choose foods high in protein such as meat scraps and pet food. You should put an amount of poison that is adequate to kill the rats.

Types of baits

Wheat based bait is normally red in color, to be used in areas where little food competition is available, check presence weekly and top up if eaten. For block-based bait, they are compressed cereal blocks that are safe and secure to be used in areas where little food competition is available, check once a week and replace if eaten. Liquid bait, this normally blue in color to be used in areas where food competition is present and mainly during hot weather, you need a dispenser to safely secure the bait. Should be placed in a sheltered environment to avoid rain. Traps have a place in the pest control market. After doing an assessment of the environment and understanding when you can use traps, control can be gained without the use of poisons.

[For more information, contact Dr Watson Messo Odwako at watsonmesso@yahoo.com]