Narcisse Snake Dens in the Interlake. Manitoba is alive with snakes! Spring is a hotbed of activity at the Narcisse Snake Dens in the Interlake. It's here that you can see more snakes at a glance than anywhere else in the world. Beginning with the first few warm days of spring, tens of thousands of red-sided garter snakes emerge from their dens and gather in large numbers to perform a fascinating mating ritual. Following a two to three week frenzy of mating activity, snakes disperse to nearby marshes for the summer. By early fall they return to their dens, wintering in fissures and crevasses of the limestone bedrock below the frozen ground. Travel tip: Sunny days are always best for snake viewing. For more information, visit Narcisse Snake Dens, check the current activity or locate it on a map.