A woman walked into the kitchen to find her husband stalking around with a fly swatter

"What are you doing?" She asked.

"Hunting Flies" He responded.

"Oh! Killed any?" She asked.

"Yes    , 3 males, 2 Females," he replied.

Intrigued, she asked.
"How can you tell them apart?"
 

He responded,
"3 were on a beer can, 2 were on the phone" !!