Invasive two-metre-long snakes are surviving in attics and walls of British homes

Sleep well

Aesculapian snakes - which grow up to 7ft long, making them one of Europe's largest snake species - are not native to the UK, having disappeared from these shores during the last Ice Age.

However, researchers have warned they are now an invasive species, and are surviving in warm corners of the UK.

After some of the snakes escaped from the Welsh Mountain Zoo, they were accidentally introduced to Colwyn Bay, North Wales in the 1970s.

Previous research found the snakes lived around the London Zoo area of Regent's Park and near Bridgend in South Wales.

But as a cold-blooded species, snakes usually need warm climates to survive, so their presence in these areas raised questions about how they were surviving.

To get a better idea of just how prevalent the non-venomous snakes are in the UK, researchers tracked 13 males and eight female snakes daily over two active seasons between 2021 and 2022.

The study found that they use “human features” of their new habitat such as “attics and wall cavities of houses” to find warmth, the New Scientist reports.

“We observed Aesculapian snakes actively seeking and returning to use inhabited buildings and were observed climbing large structures to access the attics and wall cavities of houses," scientists said.

They found that the male snakes had a "distinct preference" for buildings while female snakes preferred woodland areas.

The researchers explained that the structures such as buildings "provide shelter, thermoregulatory opportunities and egg-laying sites."

This makes the Aesculapian snakes quite unique. Most snake species native to the UK, such as the Adder and the smooth snake, tend to avoid urban areas.

Researchers believe the snakes may be using hedgerows and culverts to safely spread into new areas, in order to avoid roads.