Butler County Heritage Center, 119 W. New Castle St., is celebrating the 150th anniversary of the birth of the oil industry with two exhibits that will have planned hours from noon to 4 p.m. Sunday and April 8, 12, 15, 19, 22 and 26. Museum admission is $5 for adults, $2 for youths ages 5 to 17, and free for those younger than 5. The Butler County Heritage Center is owned and operated by the Butler County Historical Society. Call 724-283-8116.

Harmony Museum on Mercer Street in Harmony will host German buffet dinners on April 18 in Stewart Hall adjacent to the museum on Mercer Street. Cost is $15 per person, and all proceeds benefit the museum. For required prepaid reservations for either of two sittings, at 4:30 or 6:30 p.m., call the museum office at 724-452-7341.

<B>National Aviary</B>, 700 Arch St., hosts Egg Day, with a chance to learn surprising and unusual facts about bird eggs in addition to a visit with the Easter Bunny from 11 a.m. to 2 p.m. April 11. Regular hours are 10 a.m. to 5 p.m. daily. Regular 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, hosts the traveling exhibit "Exploring Trees Inside and Out" through May 17. Regular museum hours are 10 a.m. to 5 p.m. Mondays to Saturdays; and noon to 5 p.m. Sundays. Admission is $9 for children 2 to 18 and senior citizens and $10 for adults; children younger than 2 are admitted free. Call 412-322-5058 or visit the Web site, www.pittsburghkids.org.<B>Carnegie Museum of Natural History</B>, 4400 Forbes Ave. in Oakland, hosts "Dinosaurs in Their Time." 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. Regular 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.<B>Heinz History Center</B>, 1212 Smallman St., features "Pittsburgh: A Tradition of Innovation," tracing Western Pennsylvania's imprint on the world. Hours are 10 a.m. to 5 p.m. daily, except holidays. Admission is $9 for adults, $7 for senior citizens older than 61, $5 for students with ID and for children ages 6 to 18, and free for children younger than 6. Call 412-454-6000.