Some quick things I've noticed with the Weevole is that when they hide, you can still target them, and other mobs as well.
They also can't be put to sleep, this might be a design choice, but it is really odd.
Fire also kills them when they're hiding, which again might be a design choice.
Engage in fight with Weevole, hit it enough to get it to hide in the ground, when it's hiding, there'll be a small patch of dirt almost hidden, click on that or hold CTRL and F to auto attack it, you can still attack it underground and even kill it while it's hiding. Other mobs can do the same, too.