I heard something add this morning, Whiskers was playing during their out of cage time and she was making this odd little buzzing or hum sound. It really sounded like a power line does or a toneless single note hum.... It was very soft and pretty continuous. I could barely hear it and my video camera caught a little of the sound. She didn't look upset and She and Biff were like hyperactive kids out at recess, bouncing off furniture tussling with each other is rowdy play, pushing each other off the bed posts, me, the bed etc...
Is this the purring people talk about?
Squirrel giggling? I have no idea... but it was pretty cute.