You've likely heard of cats and dogs and maybe even snakes on a plane, but what about horses? Zoo animals? Millions of tropical fish?
At Frankfurt Airport in Germany, animal cargo is big business.
"We carry right around 110 to 150 million animals per year in this facility," said Axel Heitmann, director of the Lufthansa Cargo Animal Lounge at the airport. "And that's by far more passengers here than in the terminal at Frankfurt."
The Animal Lounge has nearly 4,000 square meters of space, including 42 large-animal stalls, 39 small-animal pens, 18 climate-controlled chambers for reptiles, birds or insects and a special black-light area for fish. Trained veterinarians and animal handlers provide around-the-clock care. Among the precious cargo arriving at Frankfurt on a Thursday morning were 17 polo horses from South America. Animals on the Lufthansa's passenger lists have also included bears, rhinos and lions.
About 14,000 dogs and cats pass through the facility each year. Frankfurt Airport is a point of entry for importing animals to the European Union by air, and pets must have an ID chip to prove they've had all necessary vaccines.
But by far the most-frequent fliers are fish — more than 80 million annually.
Before they can move on to pet stores, Thomas Klappich, Lufthansa's so-called "Fish Savior," makes sure they have clean water and fresh oxygen for the journey. "They can stay here 15 to 20 hours," he said.
Lufthansa moves animals all over the world. Most stay for only a matter of hours, just enough time to stretch their legs or get a bite to eat.
And fortunately, escape artists are rare, which is a good thing when you're dealing with creatures that creep — or slither.