A nesting box for cats -- also called a queening box, a kittening box or a birthing box -- provides a safe and warm environment for a cat to have kittens and care for them. It should offer privacy, ventilation, easy-to-clean flooring and raised sides to prevent kittens from falling out. Make one out of a pet carrier, a litter box or a large plastic container.
Safe Types of Nesting Boxes
Plastic Pet Carrier
A small to medium-sized plastic pet carrier is a good choice for a nesting box. It is enclosed to give your cat privacy and has holes to allow air flow, and newborn kittens won't fall out of the front because of the lip at the bottom. You can remove the door from the carrier to allow your cat to enter and leave as she wishes while taking care of her kittens.
Covered Litter Box
A new covered litter box works well as a nesting box. It has the same qualities as a plastic pet carrier in privacy, ventilation and high sides to keep kittens from falling out of the box.
Purchase a large plastic container with a lid and cut out air holes in all four sides about 2 inches round. Make one row of air holes about halfway up from the bottom and another near the top. Cut out a hole large enough for your cat to enter and exit in the lid of the container.
Think Inside the Box
The inside of a nesting box should have several layers of soft bedding for the queen and her kittens. Old sheets, towels, shirts and rags work well. Periodically remove the soiled items and replace them with fresh bedding.
Location, Location, Location
Place your cat's nesting box in an area in your home with little traffic. She will likely not use the box if she doesn't have privacy and a place to hide her kittens. The box should be placed in an area without drafts or cold air so the kittens can stay warm. A partially cleaned out closet or a spare room not in use are excellent placement options, and you can close the door if need be to assure your cat that she and her kittens are safe. Allow your cat to sleep in her nesting box, and place her food, water and litter box outside the nesting box but nearby.
Don't use a cardboard box for a nesting box unless the sides are all intact and sturdy. The box could collapse on the kittens. Also, don't use a laundry basket for a nesting box. Kittens can get their heads stuck in the slots or holes.