Rats, mice and other vermin With the advent of rodenticides numerous farmers abandoned traditional control measures. They were unaware of the dire consequences of these chemicals to the domestic livestock and other wild non-target organisms. Now, the time has come to search for rodent control methods which will not create any havoc on the ecosystem. In view of this, an attempt has been made to summarise the information on indigenous rodent control methods of the Cauvery delta, India, which are deemed to be ecologically sustainable and safe. Ever since man started to cultivate crops on this planet, he has been losing significant quantities of grains by the vermin, rats and mice. Three pairs of rodents cause ten times greater damage through their excreta. It has been estimated that in India, we lose 7 to 8 million tonnes of food grains every year due to rodents and the loss is seven thousand million rupees. To overcome the rodent's reign over the crops man has also adopted simple, economic and effective control measures against them from time immemorial. Tanjore bow trap This is considered to be one of the best tools for rodent pest control which is made of locally available bamboo. The practice of using these traps in Cauvery delta is still continuing today and the farmers are satisfied with this method. The trap is assembled by local men. The traps are placed in the evening hours in a grid pattern in the paddy fields at 3-5 m interval, and they are left overnight. The parched paddy, mixed with coconut oil, is often used as a bait material to attract the rodents. Next morning, the traps are inspected and the trapped rodents removed. The water level in the paddy fields must be maintained upto 4 inches. Burrow fumigation For this method, a mud pot of 2 l capacity is used with a hole at the centre of the bottom to blow the air at the time of fumigation. A handful of straw is burnt and the burning straw with the smoke is then inserted into pot carefully. Active burrows of field rodents are identified and the mouth of the pot is fixed in the burrow entrance. With the active burrows of lesser bandicoot rat Bandicota bengalensis and Indian field mouse Mus booduga, the burrow entrances would have been plugged by the occupant rodent and should be unplugged. The smoke that enters into the burrows makes the animals suffocate and die inside the burrows. The fumigated burrows can be opened and the death of the occupant rodent may be confirmed. Rat hunting by men In this method during night hours, three or four people group together and start to walk on the bunds of fields and inside the paddy fields with a bright petromax light and a stick. The illumination that comes from the light dazzles the moving rats, makes them inactive and immobile. Then they are blown and killed with the help of a stick. Perching poles for avian predators In this method, the noxious rodent pests are checked to a certain extent by biological means. The "T" shaped perching poles (4' - 6' in height with a 2' cross bar) prepared for the predators, especially barn owles, are planted in the fields in order to provide more accessibility for such predators to capture and gobble rodents. White droppings of a barn owl is seen on the pole. Other methods are a crocodile trap to capture rats like larger bandicoot Bandicota indica; pit fall traps (pots of 20 litres placed in the fields) and placing palmyrah leaves and/or polythene bags of which the sound at night threatens incoming rodents. Of these methods mentioned, only Tanjore bow traps, burrow digging, and planting palmyrah leaves or polythene bags tied-sticks are used. The other methods mentioned are used here and there. Nowadays, the method for perching poles is not much in use. We believe it is the right time for us to spread this knowledge among the farmers and this can help them to some extent to bring down the rodent pests population. P. Neelanarayanan, R. Nagarajan and R. Kanakasabai, Division of Wildlife Biology, AVC College, Mayiladuthurai 609 305, India. ILEIA Newsletter Vol. 11 No. 1 p. 9 P. << country/story review