This question is asked a lot in rat groups, with people posting pictures of their new rats and asking ‘what breed is my rat’? Actually, your rat’s breed is just ‘rat’.
All domestic, pet rats are ‘Fancy Rats’ (Rattus norvegicus domestica) and other individual characteristics are just varieties of this one breed. Some varieties are more popular than others, so you will often see pet shops marking up different varieties as being different breeds, such as separating top-ear and dumbo rats. This is done out of genuine ignorance, or as a sneaky way to charge more for a different kind of rat by claiming it is somehow special.
Coat Type: Smooth, Rex and Naked Rats
A smooth coated rat is the most common and is exactly how it sounds. A smooth rat will have a normal, smooth coat.
A Rex rat has a curly, or kinked coat, and curly whiskers. The curl is even across the coat, and gives the rat a more textured appearance.
A naked or hairless rat is pretty self-explanatory. They have some fuzz or short patches of hair, but are mostly hairless. A true hairless has no fuzz at all, and no whiskers, but these are unusual. Most naked rats are in fact double rexes or patchwork hairless rats. This happens from a strengthening of the rex gene, which eventually leads to hairlessness.
Naked rats need a little extra care. Their skin can become dry, but with good diet and an occasional rub with something very gentle, like coconut oil, you can easily keep their skin healthy. You may also need to offer extra nesting material in your cage, as a hairless has no fur to keep themselves warm!
You may also come across Velvets (short velvety fur) or Satin (long, silky guard hairs), but these are less common.
Ear Type: Top Eared and Dumbo Rats
Rats can have two different ear positions.
A top-eared rat has it’s ears on the top. This is the most common ear position.
Dumbo rats have their ears set lower down, on the side of their head. This gives them a sweet, sort of dopey appearance, which makes dumbos very popular. Getting a dumbo can be tricky because of their popularity, so be prepared to wait if you desperately want one. Pet shops often mark these rats at a higher price, but don’t pay more just for an ear position. They are exactly the same kind of rat as a top-eared, and they will live happily in one group.
Eye Colour: Black, Pink, Red or Ruby Eyed.
Rats eyes can be black, pink, red or ruby. Eye colour can be connected to the coat colour, and is sometimes part of the variety (such as pink-eyed whites).
A pink or red eyed rat will usually have poorer eyesight than a black-eyed rat. This doesn’t impact their quality of life, but you might see them swaying their heads in order to focus. It’s important to make a noise to let a pink or red eyed know you’re there before touching them to avoid being bitten if you startle them.
Rats fur comes in a variety of markings.
Self: One colour all over
Berkshire: Coloured on top with a white belly
Irish: Coloured, with a white triangle on the underside.
Hooded: White, with a coloured head and stripe of the same colour down the back.
Variegated: Like a hooded, but with variegated splodges of colour down the back instead of a clear stripe.
Capped: White, with a coloured head.
Essex: Coloured with a white blaze on the forehead.
You may also come across Chinchilla, Squirrel or Roan rats. Chinchillas and Squirrels are marked like their animal namesake, with coloured guard hairs. A Roan is marked like a husky dog, but may fade over time.
Rats come in lots of different colours. Your rat may be a solid colour (with this colour all over if it is a self, or just in the markings), such as black, mink, dove or blue. Flecked colours have a mix of different colours through the coloured parts of the rat, such as Cinnamon, Fawn or Silvered. The most common flecked coat is Agouti, a mix of brown, black and red shades, and the colour of rats in the wild.
Whatever variety you choose, remember that they can all live happily together, and in general a different variety needs no special treatment, unless you have a hairless rat. Having a favourite variety is common, but so is wanting to have lots of different varieties in your group. For new owners, a mix can help you tell who is who, but an experienced owner will be able to tell even identical looking rats apart by things like head shape and mannerisms. There’s no ‘best’ way here. Just choose what appeals to you and enjoy your rats.