You have visited your local shelter and suddenyl decided to adopt a kitten. Many furballs are there looking at you, with their tiny "pick me, pick, me!" voices. One though out of the blue heads towards you and it is love at first sight. The kitten evidentally likes you and instead of you picking a kitten it looks like this little kitten decided to pick you!
You play with it for a few minutes, and when the shelter assistant approaches you she asks you if you would like to adopt this little fellow. You surely are enamorated already so you commit to adopt the kitty. But before signing papers, you ask the shelter assistant if the little fellow is a boy or a girl. The shelter woman quickly picks up the kitty, takes a peak under the tail and says "It's a boy"!
You start wondering, how did she know? The kittens were so small, their behinds looked all so similar.
Telling a boy from a girl kitten takes a bit of experience. It may be a bit challenging for those not around cats much. Shelter personnel learn quickly and soon are able to distinguish boy cats from girl cats just as we distinguish apples from oranges.
However, it may be challenging even for the experts, when the kittens are days to a couple of weeks old. It happens every now and then that a veterinarian claims Sissy to be a female only to learn later that Sissy is marking territory like a full grown tom cat a few months later.
Kittens come with two openings under their tail. The top opening is the rectum and the bottom one is either the vagina or the penis. The best way to learn about the differences is to have a male and female kitten close by. The female will have a shorter distance between rectum and vagina. The male will have more distance, the reason being that this distance will allow space for the testicles to grow once he reaches puberty.
The female opening under the rectum will be a small slit, while the male's opening under the rectum will resemble more a hole.
Another thing to consider is that often calicos or tortieshell coated cats are generally female. In adult cats the differences may be more relevant. Males often have a rounder puffier face, while females have more of a triangular face. In unaltered males the testicles can be easily seen.
Now that you have learned the difference, you can give yourself a pat in the back. You are one step closer to becoming a cat expert. Your next chore then is to buy a nice kitten care book, buy healthy food and provide plenty of tender loving care.