The Zit I Found In the Backyard

Whilst weeding the sandlot and gravel areas of our back yard today, I found a very interesting creature among the unwanted nature I was plucking up. At first, I wasn't sure if it was a living organism or part of a tree, but when I touched it, its little swiveling end that I termed a head moved around and around.
It was about an inch and a quarter long, a third of an inch wide, circular, deep red, and had somewhat of a shell, except for one end, which looked like a slug's tail end. I picked up the oddity and watched it mechanically move the one part of itself that was able... and then went back to work weeding.
I showed it to my mother when she got home. She took one look at it and after realizing she had no idea what it was, told me I should show Papa Bear.
So I showed my father when he got home, and he told me to squeeze it "like a zit." Why I listened to him I can only blame on impulse. I squoze it a tiny bit before I realized it was less brittle than I had anticipated and dropped it, as white puss came out of the side of it, poor thing.
Daddy-dear thought it was hilarious.

Just goes to show, never listen to your father.