Tuesday, March 23Perhaps the last time you were at the Saint Louis Zoo, you noticed those milk crates in the chimpanzee area or that heavy-duty web/net/hammock thing in the bear pits, and you idly wondered why the animals didn't have better toys, like maybe a GameCube. Well, genius, for one thing, animals don't like video games. And also, zoos have experts who determine what's more fun for the animals, and a GameCube ain't on that list. The science of improving animal recreation time is known as "enrichment," and at 7:30 p.m. in the Living World in a lecture entitled "Enrichment: More Than Fun and Games," Ingrid Porton, chair of the zoo's enrichment committee, discusses what, exactly, that net means for those bears. Admission is $3 to $5, and reservations are required (call 314-768-5450). Maybe after attending, you'll know what to get your cats for Christmas this year.