Mike_in_SD wrote:
I have this block wall along my back yard.

it has about 3 egg size holes in it, with bee going in and out of those
holes.

I have gone out there at nite and sprayed the normal 10ft bee
spray but .. its not doing the trick
....

If it's all block and just a retaining wall as I surmise, just mix up
some mortar and patch up the holes.