A woman came home to find her retired husband waving a rolled up newspaper round his head.
Wife: “What are you doing dear?”
Husband: “Swatting flies – I got three males and two females”
Wife: “How on earth do you know which gender they were?”
Husband: “Easy – three were on the beer, and the other two were on the phone. “
This joke is included in the Black Book of Jokes. You can order it from here.