Several times after a nice, soaking rain in warmer weather I have found dead bumblebees at the bottom of my rain gauge. I figured they were after the water. Apparently I was wrong because I have been much better lately about keeping the water dumped out. Last week I went out in the garden I heard a buzzing sound. When I looked at the rain gauge there was a live bumblebee inside along with 7 DEAD ONES! This was despite the fact that it was dry in the gauge. I was devastated by this.
The solution was to glue some mesh (I chose mesh from an onion bag but a piece of window screen would work as well) to the top of the gauge so they cannot get in. I can still pour out the rain water as I did this morning. Until the manufacturers start attaching some sort of screen then out native bumblebees, that are so important for pollination, continue to be in danger from this other threat.
If anybody knows why bumblebees do this please respond or write to me.
