I've always been a morning person, but during the 2015 field season, I've discovered that my favorite time of day is early in the morning when the temperature is still cool enough that the bumblebees are cold and snoozy. Bumblebees are colony nesters, with one reproductive queen, lots of female workers, and just a few males. Oftentimes, males do not live in the colony, but spend their days drinking nectar and their nights outside. Females will sometimes get caught outdoors too, and if you're out early enough, you can catch them mid-slumber.
Bees, like other insects, are ectothermic, meaning they rely on ambient heat for their energy and produce very little or none of their own heat energy. This means that when bees are chilly, they move very slowly and don't fly readily. If you are very careful, you can pet or tickle the bees while they are sleepy without fear of being stung.
The best place to tickle a bumblebee is on its side when its wings are folded back over its abdomen. This will reduce contact with the wings, which is important because the wings are very delicate and can be easily damaged.
You can also pet them on the thorax between the wings if you are extra careful. Bumblebees are fuzzy like kittens, and when they are cold and sleepy, they won't fly away if you are very gentle.
If you are really lucky, the bumblebee will appreciate the warmth from your body and crawl onto your hand! While the bee is on your hand, I don't recommend tickling because they are in a prime position to sting if they don't like what you're doing. Just observe and appreciate your visitor! And of course, you are more than welcome to never tickle a bumblebee, and just watch their adorable, sleepy little selves on your flowers and leaves in the early morning hours.
Bumblebees are very docile. They would rather fly away than sting, and they don't seem to mind being tickled when they are snoozy and cold. If you are very gentle, you might make a new friend!