The last few nights I have seen 100 or so of these little Black caterpillars on my back concrete slab near my sliding door. They are Black with a reddish head, they are about 1/4", they walk fast, they curl in a loop when disturbed. They only come out at night. I was just wondering what type of caterpillar they are and if the are destructive to any trees or plants. I have quite a few trees and gardens and love all the insects or at least try no to disturb the ones I don't care for. Live and let live I say... Every creature serves it purpose in nature... I am just curious about them... Thanks in advance for any help with the Identity. You guys have answered several questions for me in the past and I love the education. I did an internet search with no luck finding conclusive information..