Bought a bumble bee observation hive about five or ten years ago and had a great time with it. I think i bought it at "gardens alive". Raised one nest of bumble bees with the hive mounted inside the house on the back door. Removed the door knob assembly and ran a 3/4 plastic pipe out through the door attatched to the inside hive. Everyone thought I was crazy until the nest started to develop young bumble bees. It was interesting and exciting until the nest started to stink real bad in the fall. I removed the hive and placed it outside. You can use upside down floweer pots, coffee cans, bird nest boxes on the ground to attract bumble bees in the spring. I would catch bumble bees with a glass and piece of cardboard and then place the inverted glass over the hole in the desired container to get the bumble bee to enter my bait hive. If the bumble bee has pollen on its legs in the spring do not bother it, it already has located a suitable nesting site. All the bumble bees in the spring time are queens, they mated the previous fall and spent the winter underground. Hope this helps.
"Younz" have a great day, I will.