A larger than usual number of large "fishing spiders", which live near water and love to dine on tadpoles and small fish, have been seen in northeastern Wisconsin this year, state wildlife officials say.
The Wisconsin Department of Natural Resources says is has received numerous reports of sightings of the large eight-legged creatures.
A picture of a large spider the DNR posted on Facebook, with the caption "Have you seen one of these in your yard?", was shared some 10,000 times with more than 2,000 comments by people, many of whom posted their own snaps of the creatures.
"We have been receiving reports of people finding very large spiders, like the one pictured here on a bluebird house," the DNR said in its Facebook posting.
Fishing spiders are known for their aquatic prowess, ability to run or row across water, dive, or allow the wind to sail them on the surface as they search for their prey.
These insect anglers, found in eight of the globe's 109 families of arachnids, can haul a catch five times their own weight out of the water, experts say.
Although large -- some fishing spiders can grow to be 3 inches across -- they are not considered a danger to humans.
They will bite, however, though it is usually only because "they are mishandled or feel threatened, like getting accidentally trapped under clothing," says University of Minnesota entomologist Jeffrey Hahn. Their bites are no more painful than a mild bee sting, he says.
The semi-aquatic arachnids usually live around the fringes of lakes or the banks of streams, although they are capable of moving inland for a mile or more to hunt or breed, experts say.
"Most people never see fishing spiders because they're very well camouflaged, but they're out there hunting," says DNR forest health specialist Linda Williams.
Fish-eating spiders have been discovered on all continents except Antarctica, researchers have reported.
Eighteen species so far have been confirmed as catching fish, including pond wolf spiders from India, six-spotted fishing spiders in the U.S. and great raft spiders in Britain.
It is compelling evidence that spiders are not exclusively insectivorous, says researcher Martin Nyffeler of the University of Basel in Switzerland.
"The finding of such a large diversity of spiders engaging in fish predation is novel," he says. "Our evidence suggests that fish might be an occasional prey item of substantial nutritional importance."
