A bee part of the Hostile Branch which is part of the Extra Bees add-on for the Forestry mod.
Zombies[]
Decaying Bees have a dominant effect trait called "Zombies", which spawns Zombies near the apiary at night or at low light levels, whenever players get near it.
Combs[]
They produce barren and rotten combs. Rotten combs when processed in a centrifuge have a high chance of giving rotten flesh.