Zoo That Quietly Unleashed Thousands of Horrifying 'Fist-Sized' Spiders on Unsuspecting Citizens Celebrates 'Best Year on Record' for Species

Ten years ago, a zoo released thousands of "fist-sized" black spiders across the UK to support aquatic ecosystems. Now, conservationists are celebrating the program's success.

Chester Zoo and The Royal Society for the Protection of Birds bred hundreds of fen raft spiders in test tubes, hand feeding them flies using tiny tweezers before releasing them into the wild when they were on the brink of extinction, GB News reported.

Luckily, their efforts paid off since there are now more than 10,000 breeding females across the country, marking the "best year on record" for the semi-aquatic arachnids.

"These spiders have an important role in maintaining the rich aquatic diversity found in the grazing ditches on our reserves," Tim Strudwick, nature reserves site manager with the RSPB, told GB News.

The spiders' size and agility may be intimidating—their legs span the width of a human hand and they can run across water—but they are not a risk to humans, and they can be quite beautiful if you can look past their creepiness.

"The females are impressive in size, but also beautiful—they are truly special to see," he added.