When in doubt, take the kids to see animals.
Take a trip to a local petstore or a drive to the farm and admire the horses. Whatever is easiest for mommy or daddy will work.
For my kids, going to the local petstore is almost as exciting as the zoo. The fish are swimming, the birds are chirping, and the hamsters are snuggling. Children are naturally curious. Activities like this give kids a chance to ask questions and learn about animals.
It's free, easy, and kids love it!