All About Weasels - Weasel Facts & Information

Weasel (Mustela Nivalis) Appearance & Behaviour

In the UK, weasels are small, agile mammals (They are the UK's smallest carnivore!). They have long, slender bodies and short legs, built perfectly for chasing prey into underground burrows and narrow spaces.

They have chestnut brown fur (or reddish brown fur), it is also be russet brown on the back, a creamy white throat, belly, and underside. This contrast is perfect for camouflaging in natural environments. Their face is sharp and pointed, with small round ears and black eyes, giving them amazing peripheral vision whilst hunting.

Their short tail is a key indicator in telling the difference between weasels and stoats. The weasel's tail also lacks a black tip, unlike stoats; this and tail length is a key indicator in identification.

Adults are between 15-22 cm in length and have a body weight of up to 250 grams. Males tend to be larger than females and may dominate territories that overlap those of several females.

Weasels are known to be restless, and they are constantly on the move climbing, swimming, and leaping. Weasels rarely spend long in one location—they’re always searching for prey or patrolling their territory.

What Do Weasels Eat?

Weasels are carnivores, with a diet consisting mainly of small rodent prey. They hunt with precision and immense skill.

Their favourite meals include: Field voles, Bank voles, Mice, Shrews, Young rabbits (especially in spring and summer)

If they get the opportunity, they also eat small birds and bird eggs. Occasionally, weasels will take on larger prey - killing animals bigger than themselves by delivering a lethal bite to the neck.

Weasels eat voles more than any other food in many UK habitats. Field voles, in particular, are a crucial part of their diet. Because they have such fast metabolisms, weasels must eat frequently - sometimes consuming up to a third of their body weight in a single day.

Where do Weasels Live?

The species distribution is widespread, and they are found across most habitats, including Northern Ireland, and most islands, however, their elusive nature can make them hard to spot.

They are commonly found in woodlands, hedgerows, farmlands, grasslands and edges of moorlands, including some urban fringe areas.

They choose to live in areas with dense vegetation and natural cover, as these are the areas small rodents, like bank voles and field voles, are abundant. Weasels are solitary, and each individual usually defends their chosen home range from others of the same sex.

When do Weasels Breed

During the spring and summer, weasels begin to breed (typically between April and August) - this is the time of year when field voles and young rabbits are abundant, so there is plenty of food for the young.

Before breeding, Males actively seek out females by following scent trails left in urine. They can travel large distances during mating seasons, overlapping several female territories. Once the male finds a female, he courts her through chasing, playing, and gentle biting or nudging.

Baby weasels are called kits, and a single litter contains three to six kits. If the conditions are good, the female can have up to two litters per year.

The gestation period is around five weeks, kits are born blind, hairless, and dependent on their mother. The young are raised in burrows underground, these are often old vole tunnels.

Growing quickly, after about three weeks, the kits eyes open. They begin to eat boles at around four to five weeks. By the time they are eight weeks old, they can survive on their one, leaving the nest to find their territory.

Five Fun Facts

1. The weasel (Mustela nivalis) is the UK’s smallest carnivore, but it’s a powerful predator despite its tiny size.

2. Weasels live in most habitats across the UK, including Northern Ireland and most islands—but they’re shy and rarely seen.

3. A single weasel can eat dozens of voles, mice, and young rabbits in a week. Their fast metabolism means they need to eat often!

4. Baby weasels are called kits. A female can have up to two litters a year, each with three to six kits, raised in a snug underground burrow.

5. With their long, slender bodies and short legs, weasels can chase prey through tight tunnels, making them expert hunters in even the trickiest spaces.