How Can I Stop My Cats From Mounting Each Other?

Dear Most Esteemed and Knowledgeable Kitties:

I have two brother tomcats, both unfixed and around 10 months old. This week, I have caught the smaller cat, F, humping the larger cat, A, three times. F was even biting A’s neck. I also noticed F was stimulated. It always seems to happen when A is sleeping. Is this normal behavior? Is it bullying? I’ve heard it is a way of showing dominance. A doesn’t seem to be upset by it. He just tries to ignore F. I always tend to grab him and get him off A. Why is this happening? They are getting fixed this Friday. Will that stop the behavior?

~ Bea

a pair of cats mating

Male cats do occasionally mount one another, usually as a display of dominance. Photo (CC-BY-SA) by Wikipeddia user Vmenkov

Siouxsie: This behavior is certainly evidence that your kittens are now big boys, and it’s definitely time to get them neutered!

Thomas: Most of the time, this kind of sexual behavior between two male cats is related to dominance.

Bella: That’s not to say homosexuality is unheard of in animals, of course. I once knew a pair of dogs …

Siouxsie: Bella, you hush!

Thomas: Oh, don’t be such a prig, Siouxsie.

Bella: Anyway, Bea, having A and F neutered will go a long way toward resolving this behavior issue.

Siouxsie: It’s the hormones coursing through F that are causing him to exhibit this kind of behavior.

Thomas: And maybe A is ignoring it because he’s not quite as “developed” as his brother yet. It’s probably just as well, because if they were both aggressive toms, you’d be seeing horrific fights rather than mating-type behavior.

Bella: And you still might, if a girl cat in heat comes around your house. The smell of a female in heat can make sexually mature male cats go crazy.

Siouxsie: After A and F are neutered, it’ll take about three weeks for their testosterone (male hormone) levels to zero out, so you can expect some tomcat-type behaviors for a while after the surgery.

Thomas: The good news is that if they spray after their surgery, the spray won’t be nearly as pungent as it would have been before they were fixed.

Bella: Neutering and spaying your cats is very important! It reduces the risk of disease and injury, and it prevents unwanted litters of kittens.

Siouxsie: Did you know that spaying a female cat drastically reduces the risk of mammary gland cancer and, because a spay involves removing the uterus and ovaries, reduces the risk that your cat will develop those types of cancer almost zero.

Thomas: Male cats can develop testicular cancer, too, and neutering reduces the chance of that disease to almost zero as well.

Bella: In addition, neutering male cats will decrease their aggression and roaming tendencies. This will reduce the chance that a roaming tomcat will be hit by a car or attacked by a larger animal. Because feline immunodeficiency virus is transmitted through deep bite wounds (which often happen when tomcats fight over mating rights), the risk that he’ll develop this incurable disease goes down, too.

Siouxsie: Cats can be spayed or neutered as early as 8 weeks of age. In fact, many shelters practice juvenile spay/neuter. Because they’ve been using this technique for so long, there’s a vast body of proof that juvenile spay/neuter is not in any way harmful to cats (or dogs).

Thomas: Many organizations endorse juvenile spay/neuter, too.

Bella: Okay, we’ll step down off our soapbox now. Bea, the short answer is that having your boys fixed should reduce and then eventually eliminate the behavior. Good luck.

  • Patty

    I just wondered why she has waited until they are 10 months old to have them fixed? If it were a female, she could have gotten pregnant at 6 months, so I’ve heard.

    • Judy

      My vet told me that the makes that are fixed too early don’t have there urethra fully devoloped and can have bladder issues later. Mine was about 9 months but still almost died twice last year. He is 11 now, and finally doing well again.

  • Candace

    Great answers, kitties. Keep encouraging humans to spay or neuter their pets. It’s one of the best things we can do for our furry family members.

  • Sarah Lynnae

    The kitties’ reply is excellent. I’m only commenting to note that the behavior may not be *entirely* eliminated. My cats are brother and sister. They were both altered before I adopted them, and I believe they were about 4 to 6 months old when spayed/neutered. Still, every once in a while, my boy-cat will mount his sister. It’s fairly rare, and it usually happens when we’ve opened a lot of windows after having them closed for a while. There are a number of cats in our neighborhood who roam outdoors, and my guess is that not all of them are altered, so I think my little boy is reacting to something he smells outside. It’s a bit ooky for us humans to see, but his sister tolerates him for about two seconds and then makes her irritation with such behavior clear. It’s never resulted in anything more serious than some hisses and flattened ears. Anyway, both Bea’s boys will be happier after their surgeries, though maybe not *right* after. [Grins.] I wish them the best!

  • Al

    My neutered, male Yorkie and my neutered male Persian, Skipper, were using Duke ( a neutered male Persian) as a humping post. It certainly was a dominance display.

    My Yorkie tried it on our newly rescued Snowshoe kitty and got swatted. So much for who was Alpha. From then on there was pax Nalvena and mutual respect and affection ensued.

    Sadly, our Persians and our old Yorkie are no longer on this planet….however….the good news—–

    Our twin (rescue) Yorkies and Simon, the Snowshoe kitty have rapprochement and it is Peaceable Kingdom, here.


  • Phyllis

    for heavens get the cats fixed, easy solution to the problem.

  • Victoria

    Just my observation , but it took more than three weeks after Patty O’Malley was fixed for all that testosterone to finally leave his body. Just an FYI

  • Debbie

    Get the boys fixed ASAP. The dominance play will accelerate to nasty fights in time. Do yourself and your boys a big favor.

  • Catherine Murdoch

    Sarah Lynne has a point. The behaviour may not be entirely eliminated but it may take another turn. I have both male and female cats in my household. The elder male cat, Onyx, was a rescue cat and therefore was desexed at about 10 months of age because that’s how old he was when he came to live with me. He doesn’t and has never made any attempt to hump either of my two other cats (1 male, 1 female). Instead, he humps the stuffed pink pig that lives on my bed. Sometimes he doesn’t seem to know which end he should be humping – I’ve seen him hump the head end. I’ve been informed that this humping behaviour is due to being a full Tom when he was desexed.

  • Amber @ Pooch and Puddy

    In my experience sexual behaviour is never related to dominance in animals. Sex is fun, and that isn’t something they don’t notice, considering sex is a very animal behaviour and they’re animals, duh. I’m also afraid to point out that this behaviour may not entirely go away after neutering. Egon gets… amorous… with various soft surfaces quite often. Like several times a week, that we catch. He loves him a good soft blankie. He was neutered at 8 months. A friend adopted a street cat whose neutering time she is unsure of (A neighbour owned and neutered him, and handed his gear over when she realised he’d moved into my friend’s place) and he enjoys a good humping. On his sisters (Unrelated) on shoes, on blankets, on my friend’s foot… He’s just a very loving cat.

    Humping? Totally normal. Unless one of the cats is distressed and the other won’t stop, I wouldn’t bother them. They’ll set up their own humping rules, or A will end it entirely, after they’re fixed.

  • Gabi

    Get your cats fixed what is wrong with you! Are there not enough little animals with out homes
    for you to have your cats have more!

  • Dee

    In neutered males what can this be about? My boys were both neutered as kittens, well before they reached maturity, and one of them will still jump on the other’s back and bite his neck pretty regularly. It never seems to be a full out fight, but it does seem to be a harassment thing. They’re not afraid of each other and seem to tolerate each other most of the time but now and again I’ll see this. I always worry that my poor bullied cat is going to be harmed because I know that’s where cats will deliver the “death bite” when they really want to kill something.

  • Cindy

    Quite simple: Spay and Neuter. Solves all the horny instincts! lol.