Hi does anyone know at what age you can tell the sex of a kitten. I went to help my sister choose 1. I thought theyd be the same as pups but no at almost 5 weeks old they all look the same.

Hi Sharon, really difficult at this age.  Hold belly of kitten in palm of hand with legs dangling, lift tail. 
Females, the vulva is very close to the Anus
Males, the scrot is futher away from the Anus, and at this age the scrot looks very like the vulva.
So without sounding rude, the female is the one where the two genitals are very close together,
The best way to do this, is check 2 kittens at the same time, you will see the difference

The female's "bits" can look like an upside down exclamation mark !

Though I do have to admit that I have made a couple of mistakes sexing kittens  - but there again so has a vet!!!

Margot

Thanks alot for that. Should of asked before we went to look at kittens.

To be honest as both sexes will need to be neutered by six months (to prevent them maturing and reproducing), it won't make much difference which you have.

Managing entire cats is next to impossible in the average pet environment, males if they are allowed to mature will spray and fight with other cats (neutered ones sometimes still do) and females will keep coming into season until successfully mated (and the signs are not very clear cut), unlike the bitch that cycles less often.

Yes - cats will come into season EVERY THREE WEEKS!!!! from about now, until the end of August/September.

Although some female cats will cry when on heat, not every one does - some are very discreet atbout it :D

Margot

Females can spray too....wails the voice of experience that is mine and catch the echo that bounces back from my empty purse presumed to be a bottomless pit by the furry one who sprayed anything electrical & expensive :D :D

Fortunately a spraying female is usually the result of a water infection or in my queens case a bodged neuter operation.

What type of kittens are you thinking of? Just like dogs different breeds have different temprements as can the sexes.