The lands or the floor of our houses or even outside of it are places of everyday for fights and deaths and even survivals. Outside home, usually when you see a bug which should be flying is not a good signal.
For example the 1# is a very mean one, usually is seen near bugs to kill them. this one I was really wow, because It was the first time I saw one live, and I didn't imagine it was so big!it usually kills the bugs and eat them.
About the bumble bee, even if they do the nests on the lands, if you find one very calm on the floor , there is only 2 reasons to it be like that. 1 is it has its wings wet, so it cant fly. 2. it was poisoned and its dizzy. in this one, was poisoned, since minutes after I take this picture it got crazy and fell backside and died.