in a way it's dum but it also help them prodict future viruses like them could have predicted the Corona but they was to lazy to identify it.
Answer: It helps with understanding the brain
Explanation: In the 1800'-1950's, people didn't know how to safely perform experiments on humans, so they tested this theory on mice, and they've collected a LOT of information, so ever since then, they've been doing tests on mice, and some humans.