Because all his uncles were "ants"!
or
When it's going cheep!
Did you hear the one about the crow and the telephone pole?
He wanted to make a long distance caw.
or
She ran away from the ball.
or
10. One to hold the bulb and nine to rotate the ladder.
or
None. There never was any light bulb.
Notes: Probably the only really good light bulb joke of 1984.
or