Bumble bee with white butt

This bumble bee has white hair on the rear part of its body.
Perhaps to mask that is also white on a big part of her body, due to all the pollen.
I watched the (bumble) bees in our hibiscus for a while. Some were so heavily covered with pollen that they could barely see or even fly. The hibiscus seems to be smart...
Thanks to dbifulco for hosting Tiny Tuesday.