My garden is full of them. Maybe as many as 15 different species, including some that shouldn't be here, ones probably escaped from commercial greenhouses.
My sunflowers are covered with bumble bees at the moment. I almost got smacked in the head the other afternoon by an enormous bumble bee. It was a huge species. It was so covered in pollen all over its body and its pollen sacks on its legs (like bicycle panniers) were so overflowing with pollen that it was struggling to get lift as it launched off a sunflower. It was going to collide with my forehead if I did not duck. I ducked.
If you want to encourage bees in general and especially bumble bees, plant beds of oregano. Bees love the tiny oregano flowers. Oregano is low maintenance - doesn't need much attention at all - doesn't need particularly good soil - doesn't need a lot of water - but it spreads - it is in reality a weed of sorts. Sunflowers are also good because they can last quite far in the fall.
Bumble bees are homeothermic - I hesitate say warm blooded because that is not technically correct - they maintain their body temperature independently of the environment by shivering to become warm enough to fly. This is why bumble bees are the first bees out in the spring, first bees out in the morning, last bees out in the fall, last bees out in the evening, the only bees out in the rain, and the only bees in northern climates. Other bees rely on environmental temperature to get their body up to a temperature where flight is possible.
There are lots online resources on how to make bumble bee nests if you want to encourage them to set up home in your garden. They generally do not build their own nesting cavities. They apparently
love disused mouse nests.
Interesting book:
Here is a brilliant introduction to insect and plant ec…
www.goodreads.com