Patuxent Refuge is an important stopover point for migrating ducks and geese, and September is a great time to see them on the lakes and ponds. Learn more about migratory waterfowl through hands-on activities, games and crafts for all ages. This is a drop-in program — come when you wish and leave when you’re ready. (Also Sept.10). 10am-1pm, South Tract, Patuxent Research Refuge, Laurel: 301-497-5887.