National Wildlife Refuges like Patuxent play an important role in protecting threatened and endangered species in the US. Learn more about endangered species, where they live, and some of the things you can do to help protect them in this self-paced, drop-in program. Come when you wish and leave when you’re ready. (Also May 7). 10am-1pm, South Tract, Patuxent Research Refuge, Laurel: 301-497-5887.