I saw evidence they have digestive problems when eating tomatoes.I was on an early morn strole and cam across huge messy piles and was peeeoed to think the neighbors just let their dog run at night.
It was deer and I noticed the tops of toms and middle of poile beans were gone.
This winter I added cayenne powder to birdseed I tossed on the porch.Deer had been coming to eat and tramping on the lilies. Either my pepper was old and weak and didnt even bother squirrils or it isnt the deterrent people say it is because there was a pale red area where deer had relieved themselves nearby.