It is usually made of wire or wire and wood about 2' by 3' for the smaller breeds. If you keep your hutch outside make sure it is protected from rain and hot sun, placing it under at porch is ideal. If necessary cover the hutch with plastic sheeting if it is windy or very cold. Newspapers work well for the indoor hutch to catch droppings and urine. Spaying and neutering are necessary for your rabbits.
Males benefit from neutering by eliminating spraying and hormone-related aggression.
Check with your veterinarian. If you notice your rabbit drooling this is usually an indication of misarranged teeth, which is common. The rabbit's teeth are always growing and need wearing down by chewing on twigs. The drooling means the teeth are not wearing down properly and need your veterinarian needs to do some trimming. Hairballs are a common cause of death in rabbits.