The Milwaukee County Zoo uses flex pricing and adult admission can range from $12.75 to $19.75; admission for kids ages 3 to 12 will cost $9.75 to $16.75; children 2 and younger can visit for free.

The Pittsburgh Zoo & PPG Aquarium is open daily, although hours vary depending on the season. Admission starts at $15 per adult, $14 for seniors ages 60 and older, and $14 for children ages 2 to 13.

Carol Danielson and Mary Suhl feed more than just buffalo at Sunnybrook Zoo — they’ve nurtured a tradition, named a pair of ...