Choosing what to eat can be tricky, but it’s a decision that even the simplest of animals have to deal with. Scientists recently experimented on a species of worm and saw it make complex food-based decisions. This is despite only having around 300 neurons in its brain, compared to humans’ 86 billion.
Pristionchus pacificus and Caenorhabditis elegans are two different types of worm that both feed on bacteria. However, while C. elegans doesn’t eat anything else, P. pacificus also uses its teeth to hunt larger prey – including other worms.
The scientists placed these two species together in an environment with bacteria and found that P. pacificus will kill and eat young C. elegans if it gets the chance. This not only provides a meal, but also reduces competition for the bacteria.
However, if the C. elegans were adults, P. pacificus will just bite them enough to scare them away. This means it gets the bacteria all to itself, without wasting energy fighting.
Lachlan Writes Science 