However, the occasional meal of day old bread is also ok. (Especially since your average urban squirrel probably gets half its calories from discarded pizza crusts picked out of a garbage can.)
Even though our friends over in NY published this post about a month a go, I had to link to it just for the headline: Give us this day our day old bread.
Verily, I say unto you, the linked post has some cute pictures of squirrels eating bread, in various poses. Go check it out now!