We've had our kittens for a while now and they're almost 4 months old. I bought a packet of those plastic springs and they both LOVE them! But recently Fynn has taken to carrying two of them around in his mouth while making this weird sort of rumbling noise. It's definitely not purring, it's a completely different sort of almost high pitched rumble. His brother Chester just sits and looks at him when he's doing this, or he wanders off and does his own thing.
Fynn has no problem with Chester playing with springs, and they play with them together all the time. Is he actually growling or is it just a happy noise?