Wildlife experts are dealing with a new potential threat in Minnesota's waterways.

The Minnesota Department of Natural Resources says for the first time, the signal crayfish has been found in a state lake.

Trappers caught 10 of them in Lake Winona, near Alexandria.  

The DNR says signal crayfish are bigger and more aggressive than crayfish native to Minnesota. They can spread between connected waterways and by people, and can "crawl over land at night during wet weather," the DNR says.

To view the full article and more news, follow this link to CBS News Minnesota.