Rats have probably been in Bermuda as long as people have. Rats are present pretty much everywhere in Bermuda, but they are rarely seen as they are active at night. They can be found in all habitats including small islands and caves, as well as in populated areas where they scavenge for discarded human food and trash.
There are two species of rats in Bermuda, the Black Rat (Rattus rattus) and the Brown Rat or Norway Rat (Rattus norvegicus). Both species of rats are native to Europe, but are now found worldwide after being transported on ships during European explorations. Rats are considered one of the worlds worst invasive species.
Rats were introduced to Bermuda accidentally sometime before 1614 and likely came ashore from visiting or wrecked ships. They were a significant pest to the early human residents of Bermuda, as the rats destroyed crops and ate stored food supplies. Various parts of Bermuda were burned by the settlers in an unsuccessful attempt to eliminate the growing rat problem.
Rats have had a huge impact on the natural environment. They are responsible for the decline of a number of native and endemic species. They eat the seeds and fruit of many endemic plants so prevent them from reproducing. The Bermuda Sedge in particular has become rare as the seed heads are eaten by rats before they can spread their seeds. Rats also eat the fruit of endemic Palmetto and Olivewood trees.
Our native and endemic wildlife have also been affected. Rats will steal bird eggs from nests and kill chicks, they will also eat lizards and probably scavenged sea turtle nests in previous centuries. They are known to kill the chicks of the Longtail and endemic Cahow. The only significant predator of rats in Bermuda is the Barn Owl which is relatively uncommon.