Re: If you have cats....
I've seen plenty of ginger/white females and quite a few all ginger girls, enough that when I was a veterinary nurse we always routinely checked for testes prior to neuter/spaying. They are certainly more common than calico/tortie males.
I have only seen one male tortie, it's rare, I think the guideline is something like 1:400,000......we were spaying this tortie cat and after much fishing around couldn't find her uterus until I copped a feel under the drape and there were his balls! 
We went ahead and neutered him after taking a quick photo for proof (the Royal Veterinary College is always interested in these cases). They are usually without exception infertile but like with retained testes there is a risk of the 'nads becoming cancerous so off they come.
I'm currently a slave to these two and I miss them sooooo much when I go on tour. Fortunately my husband is very fond of cats!
