A worldwide community photographing and learning about wildlife
Near a lake
I cannot tell from this far away, but they look much like Forest Tent Caterpillars to me. You may want confirmation.
Looks like gypsy moth caterpillars to me. As a child they DECIMATED the vegetation in the neighborhood I grew up in. They seem to have a large "swarm" effect every so many years and they WILL kill the trees if there is enough of them.