Joro spiders may look big and scary, but biologists say that unlike some other introduced species, they may not pose a danger to the environment, even if they spread across the East Coast. The Japanese spiders were introduced to the southeastern U.S. in 2013, and researchers expect their range to keep spreading. But these palm-sized spiders aren’t harmful to people, and biologists say they could serve as prey for birds and other insectivores. Using iNaturalist sightings and performing cold tolerance tests, the researchers found the Joro spider (Nephila clavata) can survive colder temperatures better than the golden silk spider (Trichonephila clavipes), which was introduced to the Southeast about 160 years ago. The golden silk spider doesn’t move much, but the Joro spider is likely to spread.