Black waspy looking things attacking my tree!!!! What to do?

Question

I have a very large old elm (I think) tree that now has spots of "black stuff" looks like a liquid of some type coming out of it> 2 days ago I noticed these black wasp like insects all over the tree, buzzing loud and they dont look like they are making any progress if they are building a nest, they just land on the tree and buzz away? Any ideas on what to do or what they are?

Answer 1

KILL DEM

Answer 2

there Carpenter bees my guess is hairspray and a match

Answer 3

these are called mud dabbers, they look just like a wasp but they are black, probably using the tree material in building a nest somewhere. their nest is usually made out of mud, hence the name.