Children are invited to "Build a Birdhouse," sponsored by the Sustainability Commission, on Saturday, April 25, beginning at 9 a.m. at the Susan H. Kenley-Rupnow Public Works Center, 2305 Pembroke Ave. The event is free, but registration is required, and parents must attend. Participation is limited to the first 30 Hoffman Estates children registered. To register, call the Public Works Department at 847-490-6800, or email publicworks@hoffmanestates.org with your name, number of children attending, their ages and contact information.