Ship Rat or Black Rat  Rattus rattus


HB: 182; T: 188; HF: 33; E:23; W: 139gm average.

A slender and graceful mammal, with a pointed snout, large waving ears, tail about a long as its head and body, basically 2 + 3 mammae ( with a tendency for twinning of the second pair from the front., and laminated plantar pads. Coloration of most Thailand examples are light brown, reddish brown, or buff brown on the back with pure white under parts and often with a little dark streak on the chest.


Native to Asia and spread around the world by man. In Thailand they are found in all provinces and all the islands and are the most abundant mammal in the country

Very similar in appearance to the common rat but with larger eyes and ears and longer, thinner, unicoloured tail. When in hand the ears are almost hairless compared to the common rats furry ears. Smaller than the common rat with head/body length: about 240mm and tail up to 260mm.
Weight: average approx 150 to 200 grammas with the males generally larger than to females. Pelage is grey brown above and pale grey beneath but some individuals are completely black which gives rise to the name of the black rat

General Ecology:

Ship rats are mainly nocturnal and rarely seen during the day. They live in large groups each dominated by a male and unlike the common rates do not live out of doors but  favours buildings with cavity walls, paneling and false ceilings. It climbs very well and can sometimes be seen running along pipes and even wires. It can swim but unlike the common rats does not enter water voluntarily 

Ship rats rates are Omnivores but are very often vegetarian and are very partial to fruit, most agricultural crops and in particular cereals. They live in very dense populations but vary greatly with the environment. Females sexually mature at about 90g and have an average litter size of 3 to 5  babies. Most breeding is done between March to November 

Ship Rats were once widespread in all Parts of the United Kingdom where they  spread from India to Egypt in the 4th Century and then into the British Isles during the 3rd century. Replaced by the common rat by the beginning of the 18th century and were confined to major ports, a few inland towns and small islands by the 1956 Now very rare indeed and is now probably one of the rarest mammals in Britain but in the tropics is very well established

Mortality is high among young rats who are fair game to most predatory animals.  

Ship rats will forever by associated in peoples minds with the Black Death ( bubonic plague) which caused catastrophic outbreaks of the disease in the Middle Ages


Ship rats are offered no protected by any  laws but  in theory are one of the most deserving cases for conservation action. It is indeed our rarest rodent, rapidly declining and now reduced to a few isolated populations. Nevertheless, legislation for an alien species appears inappropriate and attempts to conserve it would be widely opposed. In Lundy where a small population exists  and do little harm, its English Nature who are seeking to remove them so that Puffins can be re-introduced. Its strange that with the Puffin being one of  Britain's commonest sea birds and the Ship Rat being probably our most endangered British mammal that this should be the case.

Further Information: