sexing flies

 woman walked into the kitchen to find her husband stalking around with a fly swatted.

"What are you doing?" she asked.
"Hunting flies." he responded.
"Oh...killing any?" she asked.
"Yep, three males and two females," he responded.
Intrigued, she asked, "How can you tell?"
He responded, "three were on a beer can, two were on the phone!"

And here you thought this would be educational.....