wasp's nest near front door - kill or leave be?

[Dennis S]

Being mud and on a vertical surface, it's probably "dirt daubers" or "mud daubers." They are thin and either black or dark blue and won't sting unless you pick it up.

Pictures of nests:

http://www.google.com/search?q=dirt+dauber+nest&client=firefox-a&hs=k4u&rls=org.mozilla:en-US:official&prmd=ivns&source=lnms&tbm=isch&sa=X&ei=uT0QUtqaIoK02wX9s4GICg&ved=0CAcQ_AUoAQ