Harmony Museum on Mercer Street in Harmony is open from 1 to 4 p.m. daily; closed Mondays and holidays. Reservations are suggested for weekends and required for groups. Call 724-452-7341 or 888-821-4822, or visit the Web site, www.harmonymuseum.org.

<B>National Aviary</B>, 700 Arch St., has opened its newest free-flight space, Grasslands. Pictures with the Easter Bunny will be available from 11 a.m. to 1 p.m. Saturday. Hours at the aviary are from 10 a.m. to 5 p.m. Mondays through Saturdays and noon to 5 p.m. Sundays. Admission is $10 for adults; $9 for senior citizens; $8.50 for children ages 2 to 12; and free for children younger than 2. Call 412-323-7235 or visit the Web site, www.aviary.org.<B>Pittsburgh Children's Museum,</B> 10 Children's Way, Allegheny Square, continues "Yinz Play!" through June 6. Celebrate all things Pittsburgh in this interactive exhibit where visitors can play with Pittsburghese, repair one of the city's renowned bridges, design their own fireworks display, or help build a large-scale model of the city. The museum will be closed on Sunday. Regular hours are from 10 a.m. to 5 p.m. Mondays to Saturdays; and noon to 5 p.m. Sundays, except holidays. Admission is $11 for adults; $10 for senior citizens and children ages 2 to 18, and free for children younger than 2. Parking is $5 for nonmembers. Call 412-322-5058 or visit the Web site, www.pittsburghkids.org.<B>Carnegie Science Center</B>, One Allegheny Ave., North Side, hosts William "Red" Whittaker, director of the Field Robotics Center and founder of the National Robotics Engineering Consortium at Carnegie Mellon University, discussing "Robots at Work." on Monday. Science Center doors open at 6 p.m.; the presentation will begin at 7 p.m. and will conclude around 9 p.m. after a question-and-answer session. Dinner will be available for $8. Admission to Café Scientifique is free, but online registration for this event is recommended. Science Center hours are 10 a.m. to 7 p.m. Fridays and Saturdays and from 10 a.m. to 5 p.m. Sundays through Thursdays; closed holidays. Regular admission is $14 for adults and $10 for senior citizens age 62 and older and children 3 to 12. Parking is $5. Call 412-237-3400 or visit the Web site, www.carnegiesciencecenter.org.<B>Carnegie Museum of Natural History</B>, 4400 Forbes Ave. in Oakland, continues the traveling exhibition "Whales/Tohora" through May 2. Museum hours are 10 a.m. to 5 p.m. Tuesdays through Saturdays, with additional hours until 8 p.m. Thursdays, and noon to 5 p.m. Sundays. Closed major holidays. Admission, which includes the Carnegie Museum of Art, is $15 for adults, $12 for senior citizens, and $11 for students and children age 3 and older, and free for members and children younger than 3. Call 412-622-3131 or visit the Web site, www.carnegiemnh.org.