Every dog has his day. A cat has nine lives. Every jack has his jill.

"It's raining cats and dogs" - meaning its raining heavily. "It's a dog eat dog world" - meaning the world is a harsh unforgiving place and people will take advantage of you at every opportunity (particularly used in business scenarios). "The early bird catches the worm" - He/she who is "ahead of the game" or literally wakes up early is usually more successful or productive than others. "I'm dog tired" - I'm very very tired!

A dog is a man's best friend. A bird in the hand is worth two in the bush. A leopard cannot change its spots Barking dogs seldom bite. If you lay with dogs, you're gonna get fleas. Let sleeping dogs lay.