Officials are again finding dead ducks likely killed by a parasite on Lake Winnibigoshish and other area lakes this fall. But the numbers are smaller than in previous years.About 100 to 200 lesser scaup (bluebills) have been found on the northwestern shore of Lake Winnie. A small number of sick and dead scaup have been observed on nearby Bowstring and Round lakes, too.Although not yet confirmed, the ducks are suspected to have died from acute infestation of intestinal parasites called trematodes, which are carried by Faucet snails, an invasive species that inhabits lakes. Lesser scaup feed on the snails and become infected with the trematodes."Faucet snails have not been found in Bowstring or Round lakes, so we think the birds are moving from lake to lake feeding on Winnie but getting sick on the other lakes," said Perry Loegering , DNR area wildlife manager.DNR officials are studying Faucet snails in infested waters to learn more about their habitat use, abundance and parasite prevalence. These waters include Winnie, Upper and Lower Twin lakes, Shell River, First and Second Crow Wing lakes, and Crow Wing River.About 8,000 bluebills died on Winnie in 2007, and 2,000 died in 2008. Another 2,000 died on Bowstring in 2010.The DNR reminds hunters, anglers and other recreation boaters to check their boats, trailers, anchors, decoys and lines, and other submersed equipment when moving between waters. The best way to reduce the spread of Faucet snails is to prevent their transport.