Britain's biggest native spiders have been set free, and while some people might be terrified to hear the news, conservationists are rejoicing.

According to The Telegraph, around 400 fen raft spiders or Dolomedes fimbriatus, which can grow up to three inches long, were released into the wild by zookeepers at Surrey's Chessington World of Adventures. They have been working since 2011 to revive the population of the endangered arachnids.

These spiders have been reared and kept under their breeding program until their population doubled, ensuring that their species would not come to an end. The fen raft spiders are protected species under the Wildlife and Countryside Act.

The act of kindness has grabbed the attention of award-giving bodies in the conservation world, earning Chessington World of Adventures gold at the annual British and Irish Association of Zoos and Aquariums (BIAZA), National Geographic said.

According to Dolomedes.org.uk, a website that runs as part of the UK conservation and research program for fen raft spiders, they usually have black or brown bodies and white or cream stripes along the sides of the cephalothorax and abdomen. They have legs that can reach up to 8 centimeters. These legs have fine hairs that can sense any movement for tracking preys and predators, and are also water repellent, making them glide easily on water.

The fen raft spiders are big enough to feed on fish. And unlike how horror movies may show, they do not hunger for human flesh.

They can be pretty patient too, as they catch their prey using the sit-and wait-tactic.

Since they eat fish and tadpoles, they are usually found on lake sides and wetlands.

Buglife.org notes that only three species of the fen raft spiders are left in UK, namely Redgrave and Lopham Fen in Suffolk, the Pevensey levels in East Sussex, and Pant-y-Sais Fen and Crymlyn Bog near Swansea.

"The successful work on reintroducing the Fen Raft species is a great example of the good zoos can do in helping conserve endangered species in the wild. Here at Chessington we are very pleased to have received such high praise and recognition from BIAZA for the part we played in this project," Keith Russell, a supervisor within the zoo team at Chessington, told The Standard.