Control Measures

Rodent control is a difficult task. Simple measures cannot be adopted for rodent control. A combination of following measures often becomes essential:

a) Sanitation: Keeping the storage and surrounding area clean

b) Exclusion: Keeping them out

c) Killing: Killing those that get in

a) Sanitation: Sanitation, both outside and inside the storage structures and processing plants, helps in proper control of rodents.

• Outside and surrounding areas should be kept clean so that rodents do not find shelter near the storage area. The following measures should be taken :
• Keep bushes/weeds cut and grass well mowed.
• Make pavement around the building for 1-2 meters to reduce cover. This will help prevent rats digging under the building.
• Keep the entire area well drained. Care should be taken not to have any garbage bins near the building.
• Discarded equipment and boxes should not be dumped around the building. Do not have a garbage dump near the storage area.
• Inside area of the building should be kept clean. This creates distraction for the rats to stay inside the building. Some suggested measures are :
• Walls and floors of the storage should be smooth. This helps in easy cleaning. Walls and corners should be kept free of dust, trash and spider webs.
• All the wastes products, dust etc., should be removed immediately after any operation.
• Bags should be stacked on pallets and not directly on floor. This helps in reducing hiding cover for the rats.
• A minimum of 75 cm distance should be kept in between wall and stacks. This helps in easy movement of workers and also reduces cover for rats.
• Walls should be painted with light colour. This reduces dark corners where rats prefer to stay.

b) Exclusion:

It is an important idea to prevent the rats and birds from entering inside the storage area. Although it is a difficult task yet constructing rat-proof building and then careful operations greatly helps in controlling the entry of rats into building. Some suggested measures are

• The outer wall of the building should be of a material that rats cannot chew and should be smooth.
• A 25 cm wide rat shield should be installed at a height of 1-1.5 m all around the building. This helps in preventing the entry of rats.
• Floor of the building should be constructed at the height of truck bed height.
• Doors and window frames should be of steel and properly fixed with wall avoiding any gap between frame and wall.
• Windows should be screened with metal mesh to keep out flying insects.
• Lower 20 cm of tightly fitted doors should be covered with metal sheet lining.
• Doors should not be left open when not in use.
• Doors which are required to be left open for longer durations should be provided with transparent plastic panels to prevent entry of birds.
• Provide proper cement plaster slopes below the windows to prevent birds from making nests.
• Ensure that no board or bags etc. are kept outside the building touching the wall otherwise rats can jump over the rat shield and make entry into the building.

c) Killing:

Rats that get inside the building must be killed immediately. Different methods can be used to kill the rats.

• Field rats live in burrows. To kill these rats, one zinc phosphide tablet per burrow is required and mouth of burrows need to be sealed with mud after placement of the tablets.
• Rodents in storage premises are controlled using physical, chemical and mechanical means.
• Various kinds of rat traps can also be used to catch the rats.
• Chemical method of rat control involves poison baiting to kill rats. Zinc phosphide in food bait or ready to use single dose anticoagulant can be used for poisoning rats. Other chemicals for the purpose are barium carbonate, red squill and ANTU. Baits with slow-killing and anti-coagulant poisons are accepted by rats better than fast-killing poisons. Initially baits should be offered without poison to lure the rats to the feeding place.
• Poisoned water and feeders should be kept at strategic places inside the building. In such cases, no other water should be allowed inside the building.
• Sonic and ultrasonic repellents are also being used to repel rats.