What physical adaptation do cuckoo bumblebees often possess to survive conflicts with defending host workers?

Answer

A thicker, tougher outer cuticle

Due to their frequent engagement in brutal nest takeovers, cuckoo bumblebees frequently develop a tougher and thicker outer cuticle which offers enhanced protection against defensive stings from the host workers.

What physical adaptation do cuckoo bumblebees often possess to survive conflicts with defending host workers?
behaviorbumblebeecuckoo