Our only carrot pest, the Carrot Rust Fly, lays eggs in the soil when the carrot plants are young, and the larvae dig into the ground and tunnel into the sweet, tasty carrots. This is what they look like. It's a shame to throw away all the carrots with tunnels, so we just cut around them. They don't affect the carrots' flavor, but they are unsightly. We make our bunches just a bit bigger to make up for the damage.