Black rat

The black rat, scientifically named *Rattus rattus*, is a highly adaptable rodent.

It belongs to the subfamily Murinae and is often called a roof rat or ship rat. These animals are generalist omnivores, meaning they eat a massive variety of foods. This flexibility allows them to live almost anywhere humans exist. They are considered synanthropic, which means they live closely alongside human populations. While they are often seen as pests, they are also part of important biological systems.

These rodents have a very specific way of eating to stay healthy. They are highly selective feeders despite being able to eat nearly anything. When they find many food types, they only eat a small sample of each. This behavior allows them to monitor the quality of available food sources. It also helps them balance their nutrient intake and avoid toxic compounds. They typically forage after sunset to stay safe. If they find more food than they can eat immediately, they will hoard it in a safe place.

Black rats show several distinct physical color variants. The roof rat variety ranges from greyish black to slate grey or solid black. The Alexandrine rat is agouti and grey, often turning into slate grey. The fruit rat is agouti and pure white. While they are often black or light brown, they can show many colors. In the 1920s in England, people even bred a rare green-tinted variety. Their physical structure is quite different from the larger, more aggressive brown rat.

History shows that the black rat has traveled across the entire globe. Scientists believe they likely originated in the Indian subcontinent. They spread through the Roman Empire and reached Great Britain by the 1st century AD. They may have even arrived in Australia with the First Fleet. Their movement through Europe was linked to the Roman conquest. However, their population declined around the 6th century. This might have been caused by climate cooling or the collapse of the Roman grain trade.

Because they live near people, black rats are significant in studying disease. They can carry many pathogens, including typhus and the plague bacterium, *Yersinia pestis*. For a long time, people thought they were the main cause of the Black Death. They believed the rats spread the plague through fleas on their bodies. However, recent studies suggest humans might have been the main carriers. This is because the movement of the plague did not always match rat populations. Other Asiatic rodents may have also acted as reservoirs for the infection.

In terms of habitat, black rats are excellent climbers. They are arboreal, which means they prefer living in trees or high places. They often build spherical nests using sticks, leaves, and cloth. In cities, they prefer dry upper levels like wall cavities or false ceilings. In the wild, they inhabit cliffs, rocks, and various types of forests. Their presence in forests often correlates with canopy height and leaf litter depth. This helps them find prey and hide from predators.

Socially, black rats are territorial animals with complex behaviors. Females are often more aggressive and do not follow a strict hierarchy. Males tend to flee when attacked unless females are nearby. They often huddle together in groups for warmth or safety. Their home ranges can be quite large and depend on their gender. A male's range can be three times larger than a female's range. In some parts of India, these rats are even treated with great respect. At the Karni Mata Temple, thousands of rats live together in a sacred environment.