Mice under my hood

My car is not used for about 3 months in the winter. Last year I disconnected the battery and everything seemed fine. When I brought my car in for service, the mechanic noticed that something (probably a mouse) had nested under the hood and it had to be cleaned out - there was quite a nest! This year, when I disconnect my battery I’m considering a few options to prevent the nesting. 1. Leave the hood open so it won’t be so cozy inside and put moth balls around. 2. Leave the hood open and put a few boxes of D-con, a rodent poison which I also use inside my house. Any thoughts or other suggestions?

D-Con works but may harm other mammals. Never use it outside in an area you can’t control some access to for larger mammals. I use it but only in enclosed areas like garage. Moth balls get mixed results as do dryer sheets. Mice/rat traps lased with peanut butter under car work, but again. potentially harmful to others and larger mammals like squirrels will cart it away with them.

There are safe live trapping mechanisms you can buy or a home made drowning apparatus that works. Place near the front of the car, 5 gallon plastic pail quarter filled with water with a wire strung across the top that passes through a plastic bottle end to end. Coat the bottle with with peanut butter. As mice try to feed, they fall into the water as the bottle rotates under their weight and drown. Bigger mammals are unaffected. You need a little ramp of card board for them to reach the top, It works, is safe and effective, and CHEAP.

If winter and you worry about freezing, dump a little non toxic antifreeze or salt into the water.

Bottom line,don’t try to discourage them too much, they just mess up somewhere else. They went from my motor area when I discouraged them with your suggestions. to headliner, ate wiring and cost me $400 to fix. Trap and/or kill them. If car IS stored in the garage, you are in luck and can use several methods as one alone seldom works well.

Chipmunks are the usual culprits…Moth balls, pepper spray, will discourage them… Don’t leave the hood open unless it’s garaged…