NOVATO (KTVU & BCN) -- The Marin Humane Society is grappling with the unexpected and anonymous nocturnal delivery of 34 cats and kittens in cardboard boxes on its doorstep early Sunday morning.
It's the fifth time in four years that a large group of cats and kittens -- 130 of them so far -- were abandoned at the animal facility on Bel Marin Keys Boulevard in Novato.
Most of the abandoned cats and kittens have been black and white tuxedo cats, humane society spokeswoman Lisa Bloch said.
Security camera video showed a vehicle pulling up to the shelter Sunday and three people leaving the boxes behind. A note on one box asked the shelter to find homes for the felines, Bloch said.
"They said they feel sorry for bringing the cats, but their friend's great grandmother 'Bonnie' let things get out of control," Bloch said.
Sunday's delivery resembles the others because it happened in the middle of the night, the cats were in boxes and someone rang the doorbell at the shelter and left, Bloch said.
"While we're grateful the kitties are safe with us, we want to find out who's responsible for the over-breeding so we can offer other assistance for any cats remaining and for the people involved," Bloch said.
She said the responsible party won't be held liable or be in trouble.
"If left unattended, cats can be prolific breeders," Bloch said.
The Marin Humane Society has been vaccinating, spaying and neutering, micro-chipping and medically and behaviorally evaluating the 34 cats and kittens.
Consequently, it will waive its $100 adoption fee for all of the adult cats at its shelter until the end of September, Bloch said. She said the shelter already had 135 cats and kittens there before Sunday.
The pre-adoption expenses cost $500 per animal. None of the 34 cats and kittens delivered Sunday appear to have been spayed or neutered, Bloch said.
Anyone who donates more than $500 to the Marin Humane Society shelter will have the chance to name one of the kittens, Bloch said.
The humane society's campus at 171 Bel Marin Keys Blvd. is open Tuesday through Sunday 10 a.m.-5 p.m. and Wednesdays 10 a.m.-6:30 p.m. For more information, people can call (415) 506-6225 or visit MarinHumaneSociety.org.