Bugs climbing my house
Yesterday the back of our house (which opens onto a wooded ravine in Hamilton, Ontario) became covered in these small gray bugs - I've included pictures, sorry about the quality. They only seem to be on the bricks, not the siding, and they are on trees as well. Just wondering what they are. Any ideas?
Outside United States
This is likely the female Fall Cankerworm moth (the males are winged), Alsophila pometaria (Lepidoptera: Geometridae), a pest of hardwood trees. Visit this fact sheet from the University of Minnesota for more information on this wingless female moth: http://www.extension.umn.edu/garden/insects/find/spring-and-fall-cankerworms/.