What is a squib kick?

A squib kick is a kick where it is shorter than a regular kickoff but longer than a short onside kick, often in the last few seconds in the half. It is still an onside kick, so it can be recovered by the kicking team. In case you have no idea how long it is, it is often 25 yards or so, and it's usually kicked low to the ground, so the receiving team can't fair catch it. Squib kicks are important because I don't think it has ever been returned.