Anyone knowledgeable about bumblebees?

[YippieKayakOtherBuckets]

We have a bumblebee nest in part of a cavity wall. We are quite happy to leave them to do their thing but for the last week or so I have been finding at least one, sometimes two or three, large dead bumblebees on the ground underneath. They are so large that to my untrained eye I thought they might be queens but there are too many for this to be the case. There are lots of normal-sized small bumbles around and we see them feeding on the flowers and then returning to the nest. Picture attached - warning, image of dead bees - to show the size difference.

Does anyone have any ideas what role the bigger bees might be playing in the colony? Is it concerning that I'm finding so many dead ones? And is it a myth that they can still sting even when dead? I am checking and clearing the area before letting small DC out to play at the moment. I've tried asking the local beekeepers' association but they are all about honeybees and can't help with bumbles.

I don’t know much about bumblebees but could the larger ones be drones (males). In honeybees they die after mating

Don't nests usually produce more than one Queen and they fight it out to the death?

Thank you for responding! I just don’t know.

Just found two more crawling on the floor looking like they might be in trouble. I’ve left them to it in case they just need a rest. Saw a third very large one crawling up the wall as if it had lost the entrance to the nest (which is behind a broken brick).

I’m not very knowledgeable about bumble bees - you may have to try Google.

it could be that some of the are getting lost, then getting trapped in the room and can’t get outside to eat/drink.

some suggestions- keep the room dark if possible? Then they will only be attracted to the light coming from out side the nest.

Keep the windows open during the day - so they can fly outside.

Put down a tiny amount of sugar water - I sometimes use a bottle/ jar lid and look on Google for sugar/water ratio.

Rescue bee and put outside. Tumbler and piece of card is an easy method. Even easier is using a “spider catcher” - it’s a long plastic tube with a battery in the handle that sucks them in.

Thank you. I wasn’t clear that the entrance to the nest is external and I’m finding the bees on the ground in the garden.