As bees are active from spring, inevitably people come across dead bees, and sometimes injured bees, sometimes crawling around on the ground or in the grass, perhaps with damaged wings and generally looking a little worse for wear - although it has to be said that not all bumble bees found on the ground are dead or injured.
Kind-hearted people who see bees in poor condition crawling about in their gardens often contact me, asking for my view point on this, and wanting to know whether or not there is anything they can do to help bees in such circumstances.
I had another such query from Josh in the UK, who was happy for me to share the text of his email with readers, so that it may provide useful information to other visitors to this website. Here it is:
Here was my response:
Thank you for your email and for caring about the bees :).
I suspect you have a bumble bee nest close by. It is possible that the bumble bees have had to fight off a predator, but I suspect it is just as likely to be the case that these are older workers that probably emerged from the colony at around the same time. It is normal for workers to become ragged, and have wing damage as they near the end of their natural life cycle. You may even see a few dead bumble bees in the same area. This would possibly be due to the remaining members of the colony cleaning out the nest, part of which means removing any dead bumble bees. Again, this is normal and natural.
It is also possible that the nest has suffered predator attack. A colony of bumble bees could easily face off one or two individual wasps, but there may be a couple of casualties in the process. Had there been many wasps, I suspect you would have noticed the activity.
At this point, there isn't really much you can do, though it is kind of you to be concerned. The best thing we can all do is help bees out by having as many bee-friendly plants and shrubs in our gardens as possible, and keep pesticides out of the garden. It sounds as though you are already doing that, hence the bees in your garden :).
Hopefully, the bumble bee colony as a whole will survive long enough to produce new queens and males. If the colony manages to do this, then the colony has been successful, since they are the ones that ensure future generations.
I hope this helps.