It eats a variety of leaves including sweetgum, hickory, persimmon, and winged sumac to name a few. Here, it's chowing down on a sweetgum leaf. Notice the first three pairs of legs--they are the true legs:
Normally if you see something this "spiky" you should not touch it. Things with bright colors and spikes are Nature's way of saying "do not touch"--the animal may be poisonous or have venomous spines. Ironically, this caterpillar does not have venomous spines! It does, however, have a defense--when touched in the middle of its back, both ends will whip together towards the center--I suppose if you were a bird trying catch it, you'd be very surprised indeed! Here's a close-up of the "horns" on its head :
More in two weeks!