Site Help: Does anyone know what this is, 1 by yehudith

yehudith wrote:
I found this on one of my tomato plants this afternoon, and later found one on some kale. I've never seen them before. They're about 1/4 inch long and look at first glance like bird poop. I think they're beetles because they definetly fly. When it first noticed I was there it plastered itself down flat to the leaf and didn't move, it really looked like bird poop then. I've been finding mysterious holes in all of my plant's leaves and I'm wondering, are these causing them. Thanks in advance for your help