He said that every year, rats imparted a loss of foodgrains that would suffice to feed around 2000 million people. PAU scientists in the Department of Zoology are developing research-based technologies on rodent control under an ICAR-sponsored all-India network project.

Dr Rajinder Kaur is the principal investigator of the project. The experts working on rodent control are of the opinion that the presence of rats can be confirmed by the presence of rat burrows or holes in the ground, signs of faecal droppings, urine, gnawing of objects, tracks on dusty surface and typical musty odour associated with rodents.

Dr Sehgal said that three effective measures for controlling rodents can be sanitation, rat proofing and rat killing. He said that environmental sanitation involving proper storage and handling of food materials and refuge, prevention of its spillage, elimination of rodent shelters and physical removal of undesirable vegetation including grasses and weeds, in the vicinity of buildings and fences often prove useful. He suggested that household dustbins (garbage cans) should preferably be emptied at night before going to sleep as rodents step up their activities at night.

As far as rodent proofing is concerned, the experts suggested use of screens with 6 mm holes over drains. Cracks in building foundations need to be sealed and floors and foundations should be constructed with quality material resisting scratching by rodents. The open doors, windows and crawl space vents should have screens. Similarly, spaces beneath the doors, especially of garages and warehouses should be checked with metal stripping.

Dr Sehgal said that trapping is the preferred method of capturing the rats for killing but it can not control infestations. He mentioned that use of rodenticides (poisons for killing rats) is another option but cautioned that this measure should be used only when the rodent infestation was very high and when all other options had failed. He said that non-target animals are also vulnerable to these poisons.

Dr Sehgal further added that chronic or anti- coagulating poisons are now considered as first choice rodenticides. On the other hand, acute rodenticides are used in situations demanding a quick reduction of high density rodent population.

Like in the case of other poisonous agro-chemicals, efforts are on to identify eco-friendly approaches, said Dr. Sehgal. Giving details he mentioned that the PAU was testing herbal products in relation to rat control. He said that a product prepared by M/s Pidilite company has proved to be effective and a safer rodenticide.