Is it normal for my 4-week-old kitten to growl and hiss while playing?

HI, thanks for using Petco Pet Education Center, formerly Petcoach! I don't think that hissing during PLAY means that Ivy will be aggressive as an adult. My cats will hiss, at age 9, when we are playing with a feather stick toy. But it could be that she is warning you that she has had enough or she is annoyed with the type of play. When she gets very rough I would stop playing with her so as to not encourage that level of aggressive play. I hope this helps!

Aggression is usually associated with negative behaviors such as hissing, growling, swatting, etc. What you are describing sounds more like normal kitten playfulness, if Bella is just pouncing, nipping, or hopping around. Keeping her out of your room if she is too excitable can help keep her form hopping on you when you are trying to sleep. A pheromone diffuser such as Comfort Zone can also help her to relax and settle down some. Making sure she has plenty of toys to play with, including things you can safely play with together such as a feather on a stick or a laser pointer can help get out some of that energy without having her bite you or scratch your hands. If she becomes too excited, getting up and walking away/ignoring her until she has calmed down again can help teach her that the fun ends when she gets too excited. If she is calm and quiet, rewarding her with a treat, a play session or some attention can help teach her that's the behavior you like. If she is actually showing aggression, IE biting hard, hissing, ears pinned, low growling, swatting, etc, then I would highly recommend seeking out a trainer or behaviorist in person to address the issue and try to find the cause such as stress or fear.

This can be very normal behavior for some kittens. You should continue to stop playing when Shade begins to bite and give him an appropriate toy to play with. Make sure you are never using your hands to play. This article has some good information: https://www.hillspet.com/cat-care/play-exercise/aggressive-cat-play

Playing with feet and hands is playful but attacked with ears back and hair puffed is likely aggression. You can make sure to not play with him with your hands or feet. Only use toys to get him trained to what is acceptable and what is not. You can try feliway spays to help keep him calm. make sure when he acts out and does something wrong tell him no and stop playing with him and ignore him. This will help him do the right thing

Playful kitten behavior would be more common in a cat this age than true aggression, but it can sometimes be hard to tell the difference! :) In general, there are a few guidelines that can help. Play behavior in cats is virtually always silent, whereas growling and hissing are common with aggressive behavior. Cats who are playing will often crouch down and flatten themselves against the floor before leaping at you (or your other cat). They may also put their ears back and arch their backs, and walk sideways towards you. If it's play, the cats may wrestle, grab each other and chase each other, but there should be no injuries. If you're still unsure, you can request a one-on-one consultation and upload a video of the behavior for me to look at - I would be happy to try and help.

Unfortunately, kittens that were bottle fed can be aggressive and not as friendly. You can try to put some feliway diffusers in the House and spray her sleeping areas. Feliway is a cat pheromone which can sometimes help to calm them. Also, give her more time. She has been moved from multiple house in her short life and now around new cats (they don’t usually remember family). This can be stressful and can take weeks for them to acclimate to. I hope this helps and she starts to get use to her new living conditions.

It is OK behavior but not great. I am worried that this could escalate into a serious fight. I suggest you try using some Feliway diffusers in the house and do some environmental enrichment for them. Those two things should help. ( https://www.feliway.com/us/Products/FELIWAY-MultiCat-Diffuser ) ( thedrakecenter.com/materials/environmental-enrichment-indoor-cats ) ( https://www.youtube.com/watch?v=AejmrLa_Cs4 )