Discussing gifts on QI, the team introduced the dancing fly as an example of the many species of insect where the male gives gifts to the female in order to mate.
It's particularly prevalent amongst males who are afraid of being eaten by their potential mate such as the praying mantis and the black widow spider, to distract them while the male then mates and escapes.
The male dance flies give gifts to the females wrapped in silk, or in a balloon formed from anal secretions.
The cheekiest species captures an insect, sucks out and consumes its innards completely, wraps the empty shell in silk, and gives that to the female.
By the time the female has unwrapped the gift and found out, as it were, that her chocolate box is empty, it's too late.
The male has already mated with her and scarpered. To top that, there's one cheapskate insect where the males fool each other too.
They pretend to be female to get given a gift by a male, then they steal the gift and run off to woo another female with it.