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. Killing any?" she asked.

"Yep, 3 males, 2 females," he replied.

Intrigued, she asked, "How can you tell which are male and which are female?"

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