For those interested in native bees, here’s a peek inside a mason bee house. The primary reason we collect our mason bee cocoons is to wash off the pollen mites. Pollen mites eat food reserves left for bee larvae, thereby causing the larvae to starve. When I note the cocoons look dirty, I’m referring to the high number of pollen mites (the white dots). The frass and mud is expected and washes off easily. Just wait until I clean them. I’ll do a follow up post soon so you can see just how differen