I've seen 3-4 of these red head caterpillar things. Mostly on my garlic and one on my cucumber. This is my first year gardening and I'm very upset that they are killing my plants. What are they and how do I get rid of them? I've been picking them off and squishing them but I took this one inside to get a picture. Here he is on a garlic leaf that you can see he's been gorging himself on. Thanks in advance.