Specifically, the species falls under the family Apidae, which further subdivides into the subfamily Apinae, and then the tribe Bombini.

Sometimes the bumblebee can have a few pale hairs on top of its head, its scutellum, and/or on its tergite (abdominal segment).

Moreover, cuckoo bumblees are slightly less hairy, have shorter tongues, have more pointed abdomens, and contain much sturdier bodies than normal bees.

The forest cuckoo bumblebee can be found throughout most of Europe from the northern half of the Iberian Peninsula to southern Italy, from Greece[9] in the south to beyond the Arctic Circle in the north, and from Ireland in the west to the easternmost part of Russia.

Since bumblebee workers are solely responsible for rearing the imposter brood, the female cuckoo bee must select her host nest very carefully.

However, she must also ensure that there are not too many worker bees in case she is detected, attacked, and possibly killed along with her eggs.

If the nest she enters is well developed, then there is a chance that the worker bees will attack the parasitic B. sylvestris and kill her.

However, if the target nest is too underdeveloped, then the female Forest cuckoo bee will be unable to rear a large brood.

Before entering a nest, cuckoo bumblebees bees tend to behave similar to male bumblebees—drinking nectar until full and then resting until hungry again.

Moreover, these offspring are unable to complete worker bee tasks that social bumblebees undertake normally, such as producing wax cells and gathering pollen.

The queen also feeds on flowers such as sallow, deadnettles, dandelion, bay,[clarification needed] horse chestnut, lavender, and others.