How to tell the sex of a fly

From humor consultant Ellen.

Very interesting – I had never heard this before.

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 them apart?”

 He responded “3 were on a beer can. 2 were on the phone.”