Zoologist warns two rats can produce 15,000 in one year

Zoologist Jaanus Remm said on ERR’s Raadio 2 morning programme that two rats could produce 15,000 offspring in a year under favourable conditions.

Remm said rats can produce a litter every two months, with each litter containing 10 to 15 young. Rats are omnivores and eat almost anything, including soap and other items that can be chewed.

He said the most effective way to reduce rat numbers was to limit their access to food rather than try to kill them. Food should not be left lying around where rats can take it to their nests, he said.

Remm described poisoning as a complicated and harmful method. He said summer was the best breeding season for rats, meaning their numbers were particularly high by the end of the season. Poison can cause internal bleeding, severe pain and convulsions before the animal dies three to 10 days later, he said.

Dead poisoned rats can also endanger other animals, including pets, protected species and other wildlife.

One reason there are more rats in cities today than in the past is that there are no longer stray homeless cats roaming city streets, Remm said.

In addition to stealing food, rats can damage property by gnawing holes into walls and chewing through electrical wires and water pipes. They can also spread disease.

Remm said a rändrott can weigh up to 700 grams. Although it cannot kill a dog or cat, a large rat can fight back against a cat and injure it. He said rats do not attack people, but warned against handling them because they have very sharp teeth.

According to Remm, the rändrott is the species associated with large rat infestations, while the kodurott is found in southern Estonia.