Hello, To keep the wasps out of your bird house, I would try putting a dish containing the contents of a can of soda (Pepsi, Sprite, for example) mixed with about a Tablespoon of dishwashing liquid, (such as Dawn or Palmolive) out near the bird house. The sweetness of the soda will atract them, so don't use diet soda. Also, the dish liquid will trap them in and they can't swim out, so they drown. Then all you do is empty the container in the toilet and flush them away! I have used this solution on my deck so my cat can enjoy being outdoors too. He's a HAPPY kitty now!
I might add... my son told me to put some dish liquid in spray bottle with water, spray the wasps with a medium stream, (not too fine of a mist and not too fast,) and it works as a wasp killer because the dish liquid coats their body and it will suffocate them. This really works in a matter of seconds, too! Now, there's no need to use the chemicals that can potentially harm your pets.
