What is the technical term for "oat beetles"?

Growing up, I called these little bugs “oat beetles” because they look like a little oat with legs. They’re practically indestructible (I mean I can flick one across the room and it hits the wall and just gets up and goes about it’s business!), they’re light brown with oat like markings on their backs and from what I’ve observed, their abdomens are fairly flat looking. My little sister has suddenly taken a liking to observing bugs and I was trying to look up some cool facts about these alleged oat beetles and can’t find them ANYWHERE!!! Help would be greatly appreciated!