Kitten hissing over mouse

My new kitten, Stitch (I raised her and her siblings from 7 days old and decided to keep her), is 14 weeks old and LOVES those little mouse toys. She will play with them for hours at a time batting them and carrying them in her mouth. Today her and another foster kitten were out in the living room and Stitch was playing with her mouse. When the other kitten, Tebow, got near her she would hiss at him. She did this every time he got within a foot of her (this is the first time she has ever hissed over this!). Eventually when he got too close she would also swat at him. Obviously she is guarding her "catch"...

But is this a behavior I should correct before it gets worse ( like food aggression)?? Or is this something harmless and natural for her? If I need to correct her...what is the best way to do that?

Since she has never done this until tonight, I am thinking she may have learned this from our cat Roxy (we have been introducing them and Stitch has been subject to LOTS of hissing from Roxy the past few days)

THANKS !!!

Let Stitch have fun with her beloved mouse. I would leave her alone.

Stitch is being a cat, that is her Mouse, she has no clue its a toy, it is all she knows, and it is HERSSSSSSssssssssssssssss.
Tuffy growls with his MouMou in his mouth at ANY cat who comes close. I have about 5 different types of mice in my home and I have at least 4 of each type. With 4 cats I need to please all, and god forbid only one would rattle or have feathers. So I have a ton of mice. Enjoy your little one!
K.

I'd leave her alone too, all the cats I've had have hissed over a toy at some point if the others come too close. It's just letting the others know it's their property.

Thanks everybody!!

That's what I thought too but didn't want to do the wrong thing! It is quite entertaining to watch her do this to kittens and cats that are bigger than her!

I appreciate the help

Yes it's normal that Stitch is like that. You should see Rosie bop Sophie and Jack if they go in her space with the catnip

Gosh, old laid-back Bijou used to hiss if anyone came too close to his "bird" when he was a kitten. Aww, it brings back baby memories.