When she walked into the kitchen, she found her husband walking around wielding a fly swatter.
“Albert, what are you doing?” she asked.
“I'm hunting flies,” he said.
“Oh, I see
Did you kill any?” she asked.
“Yep, three males two females,” he replied in a confident tone.
The woman was intrigued by her husband's apparent fly knowledge.
She asked, “But how can you tell the difference between males and females?”
He replied, “Easy
Three were on the beer can and two were on the phone.”