BATON ROUGE - Whatever you do, don't call them rats. Nutria has recently been seen around the City Park Lakes, but there's no concern yet.

LSU Ag Center professor Andy Nyman says a whole bunch of nutria can do some serious damage.

"They're very good at making babies," said Nyman. "You don't have to eliminate them, you just have to reduce their numbers so they're not causing a problem."

Controlling the nutria numbers has been happening for decades. The large semi-aquatic rodents come from South America and were imported to Louisiana for the fur farming industry in the 1930's. The rodents are herbivores and feed on wetland plants. They can cause serious damage to coastal wetlands by feeding on and removing that vegetation, which affects habits for fish and wildlife, reducing storm surge, and improving water quality.

Here in Baton Rouge, the problems they could potentially present would be burrowing around the outer banks of the lakes.

"That's going to increase erosion around the sides of the ponds and lakes," said Nyman. "If it's close to a roadway it gets very expensive."

According to Louisiana Wildlife & Fisheries, about 6,000 acres of wetlands are impacted by Nutria. It's why there's a nutria control program. Since the development of the Coastwide Nutria Control Program in 2002-2003, nutria damage along coastal Louisiana has been reduced from 82,080 acres to 5,866 acres. Terrebonne, Plaquemines, and St. Mary Parishes are where the most nutria was harvested this past season. The harvest season is from November to March.

Nyman says spotting a nutria around the City Park Lakes is normal. Other than popping up to say hello, they mind their own business and humans should, too.

"They do carry a lot of diseases and parasites," said Nyman.

Open trapping season for nutria begins November 20 in Louisiana.