Bees drilling holes in walls?

[magent]

Hi,

So I have a hole in the outside wall of my house, through which I can see bees coming and going frequently. I'm pretty sure that they are bumblebees, but some googling seemed to suggest that bumblebees don't drill walls. Also, from looking at some filled-in holes in the walls, the previous owner has had this problem in the past.

With a young child in the house, I'm pretty nervous about having them there. I might be able to grit my teeth until October but how do I stop the bees coming back? It's not like I can move the house.

And how do bees drill holes in walls, anyway?

Thanks,

Jane

[gavin]

Hi Jane

They borrow tiny little electric drills, battery operated ones of course! Seriously though, bumble bees don't. They will use a pre-existing hole of the right size with a cavity of the right size behind. Old mouse holes when lower down but not up a wall. If they are bumble bees the colony will grow then disperse in late summer so your teeth gritting shouldn't last until October. Until then they are very unlikely to cause you or your little ones any bother - it isn't easy to get them so riled they will sting. Young kids running barefoot on a lawn with clover are more at risk (I remember one of mine learning a painful lesson), and that is unlikely to be influenced by your one nest.

Bumble bees don't normally return to the same spot. The queens hibernate then seek out a suitable home and seldom would reoccupy the same site. I suspect they positively avoid doing so to reduce parasite pressure. But you could always get someone to do a better job of blocking the holes in the autumn.

Is there any chance that they might be red mason bees (Osmia bicornis)? Or even chocolate mining bees (Andrena scotica)? These bees will clear out existing tunnels to some extent and the latter will share a tunnel entrance even though inside they all really act as a solitary bee with their own nest. Walls with crumbling nectar are favourites and they don't need a cavity, just tunnels. They fly for a few weeks in spring then the adults die off leaving their offspring in their tunnels for next year.

hope that helps

Gavin