You two, groundhogs are vicious beasts. They been known to kill a curious dog with their long sharp teeth. When I was a teen, I was walking my gentle husky/Shepard mix when she sniffed in the wrong place. An adolescent groundhog latched onto her face an wouldn't let go. I had to kick it several times before it would loosen it's grip. It tore a hole all the way through the side of her mouth.
More recently, I had to retrieve both of my dogs when they happened upon a huge woodchuck out back. That thing was standing up, hissing and baring it's teeth at them. Yeah, the dogs wanted a piece of it. But after my first experience there was no way I'd let that happen. I hauled the dogs away and the groundhog waddled away, standing and turning back to hiss every few steps. I put the dogs in the house, grabbed a gun, followed it and shot it dead. I wasn't taking a chance of it coming back when I wasn't there to protect the dogs.
Read this email story about a groundhog attacking his poodles an kids in his back yard.
Hedgehogs are Erinaceinae (shewlike) and groundhogs are rodents.
Doug Schwartz, a zookeeper and groundhog trainer at the Staten Island Zoo, has been quoted as saying, "They’re known for their aggression, so you’re starting from a hard place. [Their] natural impulse is to kill ’em all and let God sort ’em out. You have to work to produce the sweet and cuddly."