From the very first time mammals walked on the planet there has been both hunter and hunted. The pressure to evolve speed, endurance and maneuverability has helped them to outwit each other and occupy their very own niche. For the first mammalian hunters that came down from the trees their small size and agility proved to be a winner, but as they ventured further a field they needed to change to stay as the top hunters. In the frozen north the artic fox needs to hunt during warmer times and cache this food to survive the winter. In southern climates leopards and tigers have become solitary hunters relying on stealth and surprise to catch their next meal, coming together only to mate. Others around the globe like wolves and lions work in teams and family groups so they can tackle larger prey and better protect their young. But their efficiency as hunters makes it essential that their family life is held together and tightly controlled. With all hunters the aggression of the kill means the difference between life and death.