Four of the six lion cubs born at the National Zoo this year underwent a swim test today for their safety and your entertainment.

“All four cats were able to keep their heads above water, navigate to the shallow end of the moat and climb onto dry land,” the National Zoo says. Great Cats keeper Kristen Clark, who guided the cubs, said “it’s possible that a cub could be playing around and get knocked into the moat by a parent or sibling. We want to make sure that if they find themselves in that situation, they know how to pull themselves out of the water and onto shore.”

Two cubs, which had their own swim test in April, will go on exhibit to the public on May 9 between 11 a.m. and 1 p.m., while the other four will be introduced in mid-June. All six were sired by Luke, who they recent met for the first time.