From PBS Terra.

You might know truffles as a fancy ingredient shaved onto pasta or added to fries. Truffles grow underground and can’t spread their spores on their own. That’s when forest creatures sniff them out, dig them up, eat them, and well… pass them along. 💩This not-so-glamorous process helps truffles grow, which nourishes trees and supports entire forest ecosystems.
So while they might be a delicacy on your plate, in nature, truffles are hard at work keeping the forest alive.