It's a bot-eat-bot world at the Magna Science Adventure Centre in Rotherham, England. A herd of cylinder-shaped robots grazes peacefully, each angling its solar cells toward pools of light on which it feeds. Suddenly, a predator robot rams one of the grazers, trapping it between its metal tusks. The predator lifts the prey to its snout and sinks a single fang into the hapless robot. Vampire-like, the predator sucks away a quarter of the prey's energy to juice its own battery. It then releases the prey to forage for more light.