Well it depends what it is doing. Very slowly when the queen is looking for a nest site, and also when flying low over flowers. However when a worker emerges from the nest to fly to a known foraging site she can fly much faster than I could run when I was reasonably fit. Some foraging bumblebees have been recorded flying at 16 km per hour.
As mentioned in the life cycle page, the males emerge from the nest before the queens. When the males are not drinking nectar from flowers they fly along regular routes stopping on the way. Studies in Scandinavia have shown that each species has a favoured height for these patrols, some fairly close to the ground, and others at around 15 metres. They stop at the same places on route, there are probably easily seen landmarks, and deposit a fragrant secretion from a gland between their mandibles (jaws). This tends to happen in the morning, but they will replenish the marking after rain. Again the group of chemicals that make up the secretion appears to be different in each species. Sladen, in his book, says that this secretion has a smell that even humans could detect, and that it is very pleasant. It is not known for sure, but it is assumed that the queens detect the males by flying around at the correct height till they detect the fragrance of the males. Then mating takes place. However mating is rarely observed in the wild. The bees couple with the male hanging on to the queens back. Usually they mate on the ground or foliage, but there have been sightings of largish queens flying with a small male still attached to her. The time taken for matings also varies widely from 10 to 80 minutes. However the time taken fro the transfer of sperm from the male to the queen is only 2 minutes. The rest of the time is taken up with waiting for the sticky genital plug passed from the male to the queen to harden inside the queen's genital opening. This plug prevents the passage of sperm from other matings, so this may be the reason that the bees stay stuck together in a very vulnerable position, and may explain sightings of large queens flying around with hapless males stuck behind them. Perhaps she just got fed up once the necessary (for her anyway) bit was over.
There are many, but the big three are:
Some bumblebees have a whitish or yellow patch of hairs just below or between their eyes. In the European species and, I believe, in some American species these are males. They cannot sting, and generally they appear towards the end of the nest life, just before the new queens hatch out.
No. The bumblebee's jaws are just not strong enough. They cannot bite or gnaw through wood either.