Answer This.
 

We've all been out tou our plants and seen the honeybees and bumblebees busy collecting pollen. We all know what the honeybees do with the pollen but what do the bumblebees do with it? Are they just pollinating because instinct tells them to?
This not not an "I know something you don't" post. I really want to know myself.

Larvae
 

They feed it to their larvae. Have you ever sprayed a carpenter bee in their hole? They are the worst. Their holes are full of gobs of yellow pollen that the larvae feed on while growing.

http://ento.psu.edu/extension/factsheets/carpenter-bees

Interesting. Thanks. I have sprayed a bunch of them in their holes but have never inspected their hives. I just fill the hole with a good spray of carb cleaner and watch them bail out. When they hit the concrete a work boot does the rest.