A woman goes to the kitchen and sees her man standing with a flyswatter in his hand.
- What are you doing? – The woman asks.
- I am trying to get rid of the flies in our kitchen.
- So did you have any success?
- Yes, I’ve killed three male and two female flies.
- And how exactly did you know which one is female and which one is male?
Three of them were standing on my beer cans while the other two were on the phone.