The World's Worst Invasive Mammals
Animals as common as goats, deer, rabbits or mice can have a devastating effect on other wildlife
- By Jess Righthand
- Smithsonian.com, December 20, 2010
Common rat (© Arco Images GmbH / Alamy)
Rattus rattus originated in India and has spread like wildfire throughout the world, leaving no continent untouched. The rodents are scavengers and eat anything that is, was or ever will be edible and have contributed to the extinction of many birds, small mammals, reptiles, invertebrates and plant species. The bird decline has been the worst—it is now accepted that rats, not disease, were responsible for the disappearance of many native bird species in the 19th century, such as the Tahitian sandpiper. Rats are mostly nocturnal, which is why they can be seen scuttling around in the shadows; they carry pathogens, including bubonic plague, typhus, toxoplasmosis and trichinosis; and they breed frequently, giving birth to litters of three to ten with as few as 27 days in between.