Finding out what mice's favourite food is might not seem like it would be high on the priority list for scientists but Mr Steve Henry from CSIRO says this research will lead to more effective control of the pests.
Mr Henry said backed by the Grains Research and Development Corporation (GRDC), they investigated the food preferences of mice because they were getting reports from farmers that common pesticide, rodenticide was not giving the levels of control they had experienced in the past.
"So we started to ask questions about whether we could make rodenticide bait more palatable or more attractive to mice," Mr Henry said.
Researchers split 90 mice into three groups of 30 and fed each group a different grain, barley, wheat and lentils.
"Then we challenged mice with different food types, we broke each group of 30 into different sub groups of 10 mice and we offered them, Durham wheat, lentils and malted barley," he said.
What they found was a surprise.
"All the groups that were on lentil backgrounds transitioned to the cereal food, they stopped eating lentils almost straight away," Mr Henry said.
"While the other groups transitioned to cereals to a degree it was more like a 50, 50 or less transition.
"However, on no occasion did mice take lentils in preference to the other foods."
Mr Henry said this was not what they would have predicted with lentils containing 30% protein versus cereal which only contains 13% protein.
"We normally expect animals to target high value foods so that they get the highest value for less energy and risk of predation," he said.
"The lentils seem to have something in them that makes them less palatable to mice."
The results indicated that lentils would make a terrible substrate for rodenticide while, there were no clear differences between the cereal options.
Mr Henry said they also noticed that when they gave mice barley the first thing they did was take the husk off and eat the kernel inside, meaning if the rodenticide is applied to the husk the mice will avoid it.
Another key finding was that if a mouse eats grain with rodenticide on it and it doesn't die, it stops taking rodenticide straight away.
"It makes it feel sick so it will it will not take the bait again," Mr Henry said.
"The key message for farmers is that if you didn't get the result you wanted with your first application of bait, there's no point going out with another application the next week because the mice will not eat that rodenticide until they forget the ill effects of the initial application."
Mr Henry said it would be better to wait six weeks between applications to give the mice enough time to forget the belly-ache they got after the first application.
Try to reduce the amount of residual food in paddocks prior to applying bait to maximise the uptake of the toxin.
