The Bee was a regular honey bee which became infected with the
t-Virus either through the air, through contaminated water or from infected plants.
As their infection develops they grow roughly four to five times their original size and remarkably their wing span grows proportionally also so they retain their former agility. They were also able to deliver a dangerous poison sting repeatedly as the
t-Virus has altered their physiology to allow multiple attacks. The poison has the potential to kill a human if untreated.
They were first discovered in the
Spencer Mansion guardhouse; they had formed a large hive. It's not known whether there was a Queen as such as one was never encountered, but it's entirely likely. However, the hive and all specimens were eliminated when the mansion was destroyed in an explosion.
Based on reports by
Jill Valentine and
Chris Redfield of S.T.A.R.S., it was advised not to engage with Bees and simply flee - or if you must, use a knife. However, a swarm would cause a serious amount of injury. In terms of Gameplay, in swarms they could also stun-lock a player (essentially freezing the character into a series of stun animations, not giving them time to recover and escape which would mean a Game Over).