There is a species of ants, the Indian jumping ant, which is extremely interesting. This inch-long insect is found across the flood plains of India, and it is known to leap vertically for up to four inches and hunt prey that is almost twice its own size. As if that wasn’t amazing enough, these ants can also change the size of their brains.

A recent study has shown that the Indian jumping ant can shrink the size of its brain by 20% and then unshrink it in the span of a few weeks. The ability to increase one’s own brain size is common in other insects as well, including in honeybees, but what sets this ant species apart is the fact that it can both increase and decrease the size of its brain. The females of the species do this as they prepare for reproduction.

The Indian jumping ant is similar to most ant species in that it has a colony structure with one queen and multiple males for reproduction, and an all-female class of workers. The queen position is highly sought after, because as a queen, an ant will be served by all other members of the hive, be able to reproduce, and it will live five times longer. However, what sets these ants apart is that queens are made, not born.

When the queen of an Indian jumping ant colony dies, about 70 percent of the female workers will start to compete over the span of 40 days by fighting with their antennae. At the end of this tournament, 10 winners are left, which will become queens.

At the start of this contest, a hormonal trigger begins the physiological transformation of the participants turning them into queenlike members known as gamergates. These ants will be similar in size to workers, but their internal anatomy will be very different, with their ovaries growing up to five times in size, while their brains shrink by about a fifth, particularly in the area of their optical lobes. Researchers believe that this is due to the fact that the queen does not have to leave the nest, so it has little use for vision in the dark, underground tunnels of the colony. The central brain also goes through significant shrinkage, since the queen does not need to perform any cognitive tasks. In other words, the ant becomes an egg-laying machine.

The reason for this shrinkage is economical in nature. The brain is expensive to operate, demanding a lot of energy, energy which can be used for other purposes, such as reproduction. Of course, having 70% of your workforce reduce its ability to work would be disastrous for a colony, so after the contest is over, the brain grows back, allowing the ant to get back to work.