I did feed some squirrels in a park in Canada - Ottowa, I think - after resisting the urge to feed little mammals right through our travels in the USA.
We had been warned not to come close to wildlife because of rabies and plague fleas. Signs at the Grand Canyon really put the wind up us and we resisted all cute appealing looks until that park in Canada. I deliberately took a bag of peanuts with me and encourage the little creatures to come and enjoy a snack.
Not feeding them had been really, really hard to not do.