I'm always afraid of accidentally killing bees instead of wasps, but being allergic, I can't take the chance. I'm going to have to try this! I have like 3 different kinds of wasps that hang out at my house. I usually use a wasp trap, but I don't like having them hang all over the place. However, your nest there looks more like a hornet's nest than a wasp's nest. Do you think this would work for paper wasps too? Mud-daubers' nests look totally different.
