QUESTION:

I have a severe mouse problem in a chicken coup. I have trapped 208 of them and they are getting worse. Is a rodenticide available that can be used without harming the birds?

ANSWER:

Where oh where to begin on this nightmare job. I am assuming that this chicken coup is absolutely porous and available to the mice to enter, and that exclusion is not an option at this time? Even so, since it sounds like you are in an area with an abundance of mice available to invade the chicken area, exclusion should be a long term goal. If nothing is done in that area then you may be faced with an endless program of killing mice AFTER they get into the more sensitive coup area. The barrier would have to be complete, meaning both horizontal and vertical, since mice would easily climb over anything installed around the outside except, perhaps, smooth metal. Just a thought, but it would pay to evaluate the options for exclusion and discuss this with the customer.

You say this is a chicken "coup" rather than a chicken ranch, so I imagine this is at least on a smaller scale than a large egg ranch operation. I think the immediate answer to your question on rodent baits is that any bait that would kill a rodent would also kill chickens IF the chickens consumed the bait. However, if you properly place the bait within tamper-resistant stations and have these properly secured to the surface there should be no way the chickens could access the bait, including as a secondary poisoning. It would seem very unlikely that even dead rodents that are left laying around (which they never should be) would not be eaten or pecked at by the chickens, so any undigested bait in the rodent should not get into any chickens. It would be more up to how you manage to use the bait rather than the bait itself as to whether or not the birds can get to it.

Stand back and take a really critical look at this situation. The mice are coming from somewhere, and the best pest management nearly always involves SOURCE control - dealing with the problem where it is coming from rather than picking off the pests one at a time after they get into the more sensitive locations - in this case the coup itself. Are these mice coming from surrounding natural areas? If so, perhaps you can place rodent stations in abundance around the perimeter of the property, keeping in mind the new rodenticide regulations coming in June that require all rodenticides to be used ONLY within 50 feet of a structure. If you do place stations around fencelines and are using new-labeled rodent baits, any stations beyond that 50 foot distance would have to use traps.

You indicate that the problem is getting worse, and as always you should make certain which mouse this is - House Mouse, Vole, Deer Mouse? With weather turning warmer we can expect rodent activity to increase, and your choice of control measures may vary depending on the kind of mouse. You are in Ohio, and winter has had a hard time letting go in the upper Midwest, but outdoor rodents probably are more active by now. As my father used to say, if nothing changes nothing changes, and it appears that continuing to approach the problem as you have been, even though you are catching lots of mice, is not going to resolve it. You need to look carefully at exclusion, at perimeter baiting or trapping if possible, and somehow changing the environment around this property to make life a bit less comfortable for the mice. Customer cooperation is going to be very important. It would be unfair and unreasonable for them to create a major attraction for mice and then expect you magically to keep the mice away.