Why do I need a rigidbody for onmouseover?

I am using onmouseover in my project for many different objects. It seems that for this function to work I need a rigidbody on each of the objects that are using onmouseover as well as a collider. Why is this? From what I have found it seems that all I should need is a collider. Am I missing something or is this normal?

All you need is a collider. I don’t think it has anything to do with the rigidbody. Here are some things to check:

  1. is your collider the proper size?
  2. is your collider facing the camera?