At first you are going to be a dog in a field of squirrels.

They even complained on one that the local chipmunks and squirrels had eaten their plants in the garden (complete with photos of chewed plants) - and the remedy they sought for each of these filings was termination of the lease.

If you raise it 3%-4% every time that probably is not enough to run off a good tenant but helps protect you against unplanned expenses, insurance cost increases, tax increases, etc.

She had at times complained about squirrels and mice and I sent the exterminator out anytime she contacted me.  

All are plastic wheeled carts, and you have to roll them like 15 feet to the curb by 6am on collection day, and take them back at the end of the day.I have tried various approaches with mixed results.Allowing it to overflow results in trash being thrown into the wrong cart, or stacked outside, attracting possums, raccoons, squirrels, lizards, stray cats to rip them apart and cause a mess.Do you leave it to the tenants to work it out on some rotation schedule?  

I will eliminate squirrels/ attic pests but if they get ants in the kitchen that is on them. 

Just a thought, is it possible you have squirrels or rats in the walls or roof? 

Feeding cats or squirrels is one thing, but feeding dangerous animals like racoons, or possums? 

Reminded them they couldn't hunt squirrels or birds on the premises (didn't mention the neighbors obnoxious dog

I once got a call because there were squirrels in the attic and one had chewed through the ceiling and fell on a tenant while she was working in the kitchen:)