bumble bee's nest in the ground and early in the season, the queens are out foraging for food to raise brood or baby bee's and kick of the colony with some workers. so she can just focus on laying eggs. They can forage for several miles from their nest. so probably just looking for some food most likely. If you don't have many pollenators maybe thing about getting into back yard beekeeping. Honey bee's are much easier to keep that many make it seem. they are fun and wonderful creatures to observe. I just started beekeeping myself and am doing a Vlog series on it so you can check it out if you would like.

https://www.youtube.com/channel/UC2rcUDHm64nbp6kDUpDeiTw

While honey bees are quite easy to keep, it's even easier to encourage native pollinator bees. Simply grow a garden that has a diverse collection of plants so that there is always something in bloom for the bees and other pollinators to visit for nectar and pollen. Stop working so hard on a "perfect" lawn and introduce white clover and other low growing "weeds" that don't need irrigation, and provide nectar to a huge variety of insects. Plant flowering shrubs, preferably native types, since these are the varieties that the local insects evolved with and the shape of their flowers is easiest for the nearby pollinators to work with. There is tons of information on how to help pollinators at the Xerces Society, or Monarch Watch. Happy pollinating!!!!

Martha