Bucks are like male humans. They live for two main reasons.

Food is the first one. They will go to the best restaurant or food source available just as you would. If a hot new place opens up near you and it has a better tasting burger, you'll go there rather than eating at your regular spot. They are always going to find the best/freshest food source.

The last one being sex. When it's on it's on and that's all they think about. Just as hopefully you all are.