Gov. Bobby Jindal said Tuesday that bears have been seen in some areas, and reports of snakes moving to higher ground are common.
He said the state health department has ordered more supplies of antivenin for use by hospitals and clinics.
South Louisiana marshes are home to several kinds of poisonous snakes, including copperheads, rattlesnakes, coral snakes and water moccasins.
The Morganza spillway northwest of Baton Rouge was opened on Saturday, pouring water into wildlife-heavy wetlands of the Atchafalaya River basin.