I don't know how relevant this is, but when my 15 Y.O. son went camping this summer at Yosemite with friends I got reports back that they were "squirrel launching". They'd put a nut or piece of bread on their boot, wait for a squirrel to come along to nibble on it, then whoosh! At first I thought this was disturbingly cruel, but my son insists that the squirrels kept coming back for more rides.