Besides being in heat, are there any other reasons for constant howling? My baby girl, who I adopted a month ago, started howling at all hours about four days ago, particularly at night. I'm on my fourth of five nights without sleep and at my wits end. I'm also afraid my neighbors are going to complain to the tenant manager. She's supposed to have been spayed and there's no blood in the litterbox, but all other signs point to heat. She very affectionate, the howling and the constant need to be near a window or door. I really, really need sleep and some peace of mind as my other cat has been admitted to hospital, so if someone could help, I'd really appreciate it.