13 November 1998

Rat bait – back to 60s

WITH no new rat poisons on the horizon for at least five years and resistance a growing problem, CSL scientists are pinning their hopes on modifying an effective but distasteful product from the 1960s.

Highlighting the increase in the ability of rats to survive previously effective poisons, Dr Wildey said micro-encapsulation to disguise the taste of the old chemical could offer a way forward.

"We are now at the point where we are getting regular failures of even good treatments." Supercharged rats, those able to eat large quantities of current poisons with no harmful effects, pose a particular threat to other wildlife, he added. "37% of barn owls contain significant residues of anti-coagulants."

&#8226 In 1992 98% of animal feed mills had rat control programmes, but the rodents were still found in 73%, noted Dr Wildey. "Just to have something in place does not mean it is working."