I also think that many times they will simply chuck them off the front entrance or within a foot or two, where in the summer, they may fly 100 feet out, drop them, then return.
The first time I placed hives on a concrete pad years ago, I was shocked how many bees were dead around the hive. In a field or in the yard, you really do not notice many. But place them on a concrete pad or a sheet of rubber, and then it looks like many more.