Pyramid Mountain Natural Historic Area, 472 Boonton Ave, Boonton, NJ 07005.

Ages 5 & up.

How hard is it to build a nest that is sturdy, comfortable, and camouflaged? After examining real birds' nests for clues, try your hand at making a home that a bird would approve of. Play a wild game about what it's like to be a parent or baby bird, and finish with a craft that will help birds around your house make their nests.

Cost: $12 per child.