Creepy Crawlies

Do they have orange spots on their backs?  I can't quite see. I'm guessing they're mourning cloak caterpillars (aka spiny elm caterpillars). Bt is said to be effective on them, if it's worth it.

Wow, I looked up mourning cloak caterpillars and here is what I found.  This is a very informative site.  I love mourning cloak butterflies but never knew the caterpillars looked like this. 

Mourning Cloak Caterpillars, Not Gypsy Moth Caterpillars

I can't resist posting some more info about the mourning cloak.  There is also a photo of the caterpillar if you scroll down. 

Mourning Cloak Butterfly - Nymphalis antiopa

Do they have red dots, kerc? If they are mourning cloak caterpillars, they won't kill your tree, and soon they will all go away without your doing anything.

Thanks for the info. We think they have red dots (it's early morning now). I'm reassured that we don't have gypsy moths or some other such pest.

My neighbor, being in a new house with new gardens to her, noticed many caterpillars crawling on a garden plant. She started to kill them until she realized, with my prompt, that they were Monarchs on a milkweed plant, the garden being a butterfly garden. Always check before freaking:-)