Double Rex Rat

Coat and looks how to spot one

Sparse, patchy rex coat (two copies of the rex gene)

A double rex carries the rex gene twice, which gives a thin, uneven coat. Over its life the fur grows in and moults away in changing patches, and at times the rat may wear a very short, even coat all over. The whiskers are curly and shorter than a smooth rat's.13

Personality what they are like

The coat genes do not change personality, so a double rex is as curious, affectionate and trainable as any well-handled fancy rat.36

Daily activity how busy a day looks

As lively as any fancy rat. Most active around dusk and through the night, it needs daily supervised time out of the cage, things to climb and forage for, and short play or training sessions.67

Grooming and care the hands-on bits

No brushing is needed. Because the coat thins and regrows in patches, keepers should expect its look to change from month to month; this is normal for the type. A warm, draught-free room and plenty of soft nesting material help a thin-coated rat stay comfortable.17

Home where they are happiest

The largest multi-level rat cage you can fit, with shelves, ropes, ladders, hammocks and hideouts, dust-free bedding such as shredded paper, placed in a quiet room around 19-23 C away from direct sun and draughts.74

Food basics what goes in the bowl

A complete rat nugget or pellet as the daily staple, with small portions of vegetables, a little fruit, grains and cooked egg counted into the ration. Keep sugary or fatty bits for training rewards, scatter some food to encourage foraging, and provide fresh water from a bottle at all times.8

Company who they like around

A very sociable animal that should share its home with at least one other rat, in a same-sex pair or small group or a neutered mixed pair, and enjoys daily time with its people.63

The story where it all began

Once the dominant Rex coat reached fanciers from 1976 onwards, breeders found that pairing two Rex rats could give some babies two copies of the gene. These became known as double rex or patchwork rats, and AFRMA documents them as genetically sound animals with a typical lifespan.213

Recognised by the official bits

American Fancy Rat and Mouse Association (AFRMA)

Not one of AFRMA's seven standardised varieties; AFRMA explains it as the homozygous (ReRe) form of the Rex coat.1