We've had at least two IOTD's (both by UT) about tent caterpillars. They look enough alike in the posts and in my neighborhood to make me wonder about these.
IOTD's for 8/8/06 and 6/5/10
http://cellar.org/iotd.php?threadid=11424
http://cellar.org/iotd.php?threadid=22880