I smashed up some tofu, put it in the usual dish, and brought it over to the Finsterium. Tea didn't hover this time, but he saw me, left the tasty seeds he'd been snacking on, flew up to a perch, and watched. He was the first to try some tofu, and the rest of the Societies were right behind. Goober is on the left in this picture, and I'm pretty sure that's Tea on the right.
With the exception of lettuce and maybe corn, I've found that if I give the Finsters the same food every day they'll lose interest in it. I think half the fun of food is exploring a new item, which is why I consider food to be a pretty good toy for a Finster.
I offered Peanut some tofu from a spoon. He started squeaking, and proceeded to flick most of the bits off the spoon. Food can be a pretty good toy for Peanut, too, but I still like to think he gets just a few molecules of the substance in him.