Who Let in The Bees?

If A's hire A's and B's hire C's, 
The question at hand's: "Who let in the B's?" 
The B's will take over -- they're killers, you see! 
"Aye!" shout the A's. "We can't let it be!"

But the damage is done -- the B's have a hive. 
All's left is to run -- while the place takes a dive. 
"No!" cry the A's. "Our dreams are in there!" 
"Oh?" say the B's. "Show us just where."

There, the A's falter, for B's have a knack 
To swarm like a bastard and drive the A's back. 
B's win in the end -- as every A sees... 
At root is the problem: some A's let in B's.

Copyright 1998, Mike Levin