I already had my bike 'put up' for the winter when I decided to remove the battery so that I could bring it inside the house.
I'm really glad that I did because that was a HUGE mouse nest behind the battery. The lil bugger had a very good supply of what looked like bird seed and a nice nest made from my garage insulation. No longer. Instead it will find a block of poison where it's nest used to be. Bon Appétit!
WELL... go a little further and do some more examining...
I've never had a nest in the battery cave, but I have had them 3 different times, up on top of the engine, around the throttle position indicator... they love that spot, probably because it is soo much work to get to... and when they chew up the harness to the TPS, its a royal p.i.t.a. to re tape and insulate that wire bundle... buried deep inside, and attached to the sensor, which requires major work to remove it...
also, look under the seat, in the back, behind the relay box.... in that cave back there... they love that spot also... and chew the bejesus out of that harness when they nest there... I had to repair 15 wires in those harness...
Luckily in every event, I had taken the time to pre-examine those areas, prior to spring "startup", after finding the first nest during a winter service years ago... having not done the nest removal could have resulted in a catastrophic fire and meltdown, on a "first ride" scenario, with the nesting material blowing around and landing down inside the fairing on the header area...
all the "mouse prevention lore" is just useless... peppermint oil, mothballs, dryer sheets, etc... are worthless.. simply don't work... I hate Meeces to Pieces....
I poison them with bait traps, and trap them in "drowning buckets"..