Fly gender
A woman walked into the kitchen to find her husband stalking around with a flyswatter.
What are you doing? she asked.
Hunting flies, he responded.
Oh. Killing any? she asked.
Yep! Three males and two females, he replied.
Intrigued, she asked, How can you tell them apart?
He responded, 3 were on a beer can, and 2 were on the phone.