its a dog-eat-dog world

Its a dog-eat-dog world is a phrase often used when someone is talking about a situation where people need to look out for themselves and their own interests first because this is what everyone else is doing. This idiom refers to the fact that dogs in the wild are only out for taking care of themselves, such as finding food and wont worry about other dogs; in life, you sometimes have to behave in the way that is for your own benefit.