Why is my 4-month-old female puppy humping objects and pillows?

I wouldn't be alarmed by this as it is likely a behavioral problem. Mounting, thrusting and / or masturbation in dogs is a normal behavior. However, excessive amounts of this can be problematic and may need to be addressed by a behaviorist. An occasional episode of humping should not be a cause for concern and neutering does not always fix this 100% of the time. If it becomes excessive, I would research a behaviorist in your area and schedule a consultation. Please feel free to contact me if you have any further questions / concerns

Humping behavior is not restricted to male dogs and we often see females performing this behavior. It can be a result of excitement or stress but in some instances can be a form of dominance or aggression. You can try to distract/discourage your dog by offering a toy or play when your dog starts this behavior, or teaching your dog the "leave it" command and applying it to other dogs she may approach. If the behavior is excessive or becoming more aggressive then a consultation with a veterinary behaviorist is recommended. Here is an article with a little more information on ideas to deal with this behavior: https://drsophiayin.com/blog/entry/poodles_embarrassing_greeting_behavior/

This behavior is often considered part of a dominance issue and can be seen amongst any dogs, even neutered dogs occasionally. Be aware that your puppy will be able to mate very shortly and you should consider neutering her or making arrangements to keep them separated for 3weeks when she comes in heat next

Humping in dogs is not always a sexual behaviour, but in some cases spaying may help, so I recommend talking to your vet about having Mia spayed. Also visit the following link for more information on the why dogs hump https://www.purina.com.au/dogs/behaviour/humping .

Humping is not only a sexual behavior, it can also be a dominance behavior, a stress response, etc. Any new changes lately - new pet in the home, any major changes in his routine or in the house? I suggest you refer to this article for more information. Hope this helps. ( https://www.aspca.org/pet-care/dog-care/common-dog-behavior-issues/mounting-and-masturbation )

Quite often humping has not a sexual behaviour in dogs but a behavioural meaning, often secondary to conflittual emotions such as overexcitement. In your case, it is quite obvious that it is nothing related to sexual mating but rather something behavioural that it is often shown in the normal repertoire of dog’s behaviour.

Bailey is a cutie! At this age, the mounting is a sign of dominance or just a response to excitement (nonsexual). I would only be concerned with teaching her appropriate doggie manners as not all dogs take kindly to the behavior. I hope this helps!