Because you put a hat on a cat that you pat, you don't do that to a rat or mat.
You can step on all of these but two will fight back and one wont. Two will bite back and one wont. One will scratch and bite, and the other will just bite. Two will cry out but not in the same way. Only one will take it lying down.
LOL. Because the cat sat an the mat and ate the rat.
Open your eyes before you pet it.
The clue is in the spelling :-)
"C", "R" and "M"
"C"at, "R"at and "M"ats!
I sat on the matt and all was flat