Glossary:
Underneath - below; at a lower level or position
Squeaking -  having or making a high-pitched sound such as that made by a mouse or a rusty hinge
Wheel - a solid disk or a rigid circular ring connected by spokes to a hub, designed to turn around an axle passed through the center
Crunch - the act or sound of crunching (chewing with a noisy crackling sound)

References:
http://www.gocomics.com/
http://www.thefreedictionary.com/