Do dogs know if they're biting something that is alive?

Oh yeah they do. My brother’s dog would nip a little in the house. Mostly playful. I went into his pen one day. He didn’t like that at all. He chewed on me hard. I didn’t back down and kept after him to stop. But I began to wonder a little, because he bit me hard. It was quite a battle, but he didn’t quite draw blood. I got him to stop and he hasn’t done it since, but he knew exactly what he was doing. Both arms were scratched up bad and the next day they were black and blue from my wrist to my elbow.

Sure do. Cats, too.

Even if the living thing is something or someone they don’t like they can bite. Hard.

I think they learn more discrimination than that. Our dogs knows he can clamp down on me moderately hard, but has to be much gentler with his mom. he will also be very gentle if somone plays tug of war gently with him but fierce if his opponent acts fierce.

Our one-pound parrot knows what she’s doing with her beak.
She can give you the sweetest nibbles with tenders licks from that strange little black tongue. But she can do serious bruising and draw blood if she feels threatened.
If she’s working on pellet food, a bird toy, or her “wrestling rag” there will be crunching. She can destroy wood.

My sister had a German shepherd that was so gentle when playing with her young daughters. This is a dog that was trained to “take a person outside” on command. He would chomp down on the person’s arm, without breaking skin, and literally escort them out the front door. Then one day, he crossed over into the neighbor’s farm and killed a sheep.

In all three cases, I think that he knew what he was doing to a living creature with a pulse. One was play, one was defense, and one was just plain animal instinct.

Yes, dogs and cats and parrots and horses. They all KNOW when they are being too aggressive if properly trained. I have had all of these animals and every one KNOWS the words ” No biting!” or ” No Claws!” which I say to my cats. My geese as well. They also know the ” no biting” phrase.

Hard to be sure what triggers play behavior vs. hunting or fighting behavior. Dogs are social animals, but does their social behavior imply a cognitive distinction on their part between animate and inanimate?

I was going to post a couple of relevant anecdotes but decided they were too gruesome.

Sure they do. My dog was a puppy and liked to play tug of war with a rope. If he got too excited and accidently nipped my fingers and I just said ouch, he would stop and lick my fingers. Funny thing is no one taught him that. He was his immediate reaction. He never bit down as hard as he did with the rope. Which would mean he had to know when he made contact with flesh. I don’t know if it was the word ouch that made him do that or if maybe his real mom taught him it wasn’t nice to be too rough and would nip him back and licking her put him back in her good graces.