Hi Rhonda!
Absolutely. Disney's Animal Kingdom is one of the four major theme parks at Walt Disney World. The theme parks are open every day of the year, though not every attraction in necessarily open. You can get the operating hours for May
here. The park is currently scheduled to be open from 9:00 to 5:00 every day that week.
If you have any thrill ride fans in your party, be sure to experience Expedition Everest and Dinosaur. Expedition Everest is a spectacular roller coaster; it is my 10 year old's favorite attraction at Walt Disney World and has become a "must do" on every trip. I recommend experiencing Kilimanjaro Safaris early in the morning; it's been my experience that the animals are most active early in the morning, especially during the hotter times of the year.
If you need a dining recommendation, I highly recommend Tusker House. It is an all-you-care-to-eat buffet with African flavors. I think it is great'; my favorite buffet in any of the theme parks. Tusker House is also home to Donald's Safari Character Breakfast. If you have young children, they may enjoy that experience.
If you get the chance, be sure to watch Mickey's Jammin' Jungle Parade. I think it is a fun parade to watch. I especially enjoy watching it from the second level of the Yak and Yeti Table Service restaurant; there are a few tables near a window that over look the parade route. If interested, be sure to get an Advanced Dining Reservation; I recommend getting one for 30 to 45 minutes before the parade.
Have a magical vacation!