Improved rodent-free grain storage

How to detect rats

Squeaking and scratching noises

- Odour
- Rat droppings and urine marks
- Burrows
- Damage, such as torn bags, spoiled grains
- Chewed window and door sills
- Feet and tail marks on dusty floors, shelves, or table tops
- Grease marks

Prolific pests

Factors contributing to high rat population:

The life span of a rat is 12 to 18 months.

- Rats breed continuously throughout the year.
- First menses begins 4896 hrs after puberty.
- Rats are sexually mature at 6 to 11 weeks..
- A female gives birth to 5 to 21 young at one time.
- A female reproduces 4-6 times in a year.

Rats are a costly, unhealthy nuisance virtually everywhere they spread disease, destroy crops in the field, destroy stored food, damage household property, and damage forest and fruit trees. Rats consume and destroy more than 20 million tonnes of field crops, and more than 33 million tonnes of crops in storage around the world each year. In India alone, rats damage 11 million tonnes of crops annually with their urine, parasite carrying faeces, hairs, and secretions.

Control

There is no way to get rid of rats completely. Rats can, however, be controlled through a program of prevention and destruction.

Rat prevention

- Keep food in rat-proof containers.
- Keep left-over food in bins with tightly fitted lids.
- Do not pile rubbish, timber, or bricks near grain stores.

Rat destruction

When fields are flooded during monsoon, rats remigrate and concentrate near residential areas for food and shelter. As well, rats tend to breed during the rainy season. Therefore, though rats should be controlled throughout the year, trapping and poisoning rats during the monsoon is most effective.

Note

Trapped rats should be drowned in their cages in a pond.

Mechanical methods

Traps

Field rats-Bamboo bow and arrow traps, pot traps and break-back bans are useful for catching field rats. Break-back traps, as their name implies, are deadly.

Household rats-Rat trapping is an age-old practice. Spring traps and multiple cage traps are common for protecting food in

Some types of traps

Iron cage

Wire net cage

Wooden cage

Prevent entry into grain storage areas

- Plug holes with pieces of glass, cement, and plaster.

- Make sure doors fit tightly. Construct a solid platform 75 cm high-without steps or ladders-on which to store your grain.

- Fix metal sheets at the base of the door.

Flooding and smoking

Flood and smoke rat burrows in the field. For best results, this should be a coordinated, community effort, targeting as many rat burrows as possible.

Clubbing

Cornered rats can be clubbed with long, heavy sticks.

Chemical methods

Chemicals that kill rats are known as rodenticides. They can be single-dose or multiple-dose poisons. Among these are: zinc phosphide, barium carbonate, Warfarin, Rodafarin, Pival, and Restions. These compounds are highly toxic and cause rats to haemorrhage.

Types of bait

Three types of bait are generaly available.

Ready-to-use Rats can be fed directly when bait is of the ready-to-use type.

- Dry concentrate - Thoroughly mix 25 g of bait with 450 g of wheat flour, 10 g of edible oil, and 15 g of sugar or jaggery Do not add water.

Water-soluble baits-These are useful in rat reduction campaigns when rat infestation and temperatures are high. Mix one part bait with 20 parts of water. Put in a shallow container from which rats can drink.

How to use bait it, Before any poison is used, train the rats for a few days to eat unbaited food. Put the food in shallow containers and place these along rat runs and dark areas where the rats can eat without being disturbed. This makes the rats used to feeding on a particular food. This is called pre-baiting. After a time, add the poison to the bait.

Baits can also be pushed into rat burrows. This is called "torpedo baiting

Note

Dead rats should be buried.
Unburied dead rats are a health hazard and pollute me environment.

Delayed - action baits

Zinc phosphide kills rats instantly. Warfarin and other poisons kill after 6-7 days.
Rats are intelligent animals.
After a few rats die from zinc phosphide, other rats or 11 not eat this bait. Use Warfarin or other delayedaction poisons to ensure effective control.

Caution

Keep bait away from poultry and children.

After eating bait, rats look for water to drink. Therefore, keep all your drinking water protected, away from rats.

Rat damage to various crops In India:

Contributor Dr. L. M. L. Mathur