The Essex County Environmental Center’s “Little Explorers” program is holding several of nature classes for kids in August. There will be sessions for 2½ to 3½ year-olds on August 2 and 16, from 10 to 11 a.m. Children ages 3½ to 5 meet on August 9 and 23, from 10 to 11 a.m. Each class costs $6 per child, although additional material fees may apply. Space is limited and advance registration and payment is required. All classes meet at the Environmental Center in Roseland. For information, call 973-228-8776.