Do butterflies have brains? Yes, like other life forms, the butterfly brain is its control center and sends and receives signals throughout the body. Butterflies start off as eggs, develop into caterpillars, and undergo metamorphosis to become butterflies. During this transformation, most parts of the caterpillar's body, including muscle and other cells, are broken down and rebuilt. However, the caterpillar brain cells are reused and adapt to control the butterfly's new parts.
Some of the best questions are from young scientists. Take for example this question about butterfly brains from a 5th grade student. Greer asked if a butterfly's brain is the same as when it was a caterpillar. Now that is a fantastic question.
To begin to answer this question, let’s talk about brains and brain cells. As you probably know, the brain is the control center for most animals, including humans. This is where signals are sent out and received by the rest of the body. These cells can help an animal move by controlling muscles, or transmit information about its environment and make changes according to what is happening. If it is too hot, it might signal muscles to move to a shady location. If there is a predator, it might signal to hide or even change color to blend into its surroundings.
This is all pretty straight forward for most animals - except for those who make big changes during their life, such as a butterfly. These animals begin life as an egg that develops into a caterpillar. As a caterpillar they move by crawling around plants and eating. They eat a lot during this period and move around a lot. You can imagine what a caterpillar’s brain needs to control. Finding the best plants to eat. Moving around the plant. Eating and processing food in order to prepare for their next stage in life. This is where they change from a caterpillar into a butterfly. This is called metamorphosis and it is one of Nature’s most fantastic feats where an animal changes from one form of animal into a very different animal.
Once they make the change from a crawling, eating, and pooping machine into a flying, mating, and egg laying butterfly, their brain has different parts to control. So, does the brain transform like much of the caterpillar when it goes through metamorphosis to become a butterfly?
Most of the parts, like muscle and other cells are broken down and their materials used to build new parts, like wings and antennae and new muscles are constructed to move the new parts. The brain and its cells are a different story. The existing brain cells are reused to control the new parts. So old muscles that were used to crawl are remade into muscles to control the wings, but the nerve cells in the brain remain the same. They adjust to their new role and help the new butterfly during its new stage of life. It’s a reminder of the fantastic nature of Nature.