Let's put it into terms that you can understand. Bats who bust a nut with many other bats are well hung so they can be better at busting a nut than the other bats. Because so many resources were diverted for , they're a little lacking in the melon. The bats who bust a nut with only one other bat are gay.
Gary,,I believe he was being facetious; hence, my "laying-off promiscuous bats for a couple hundred generations" jocose suggestion.