- Ferrets are really neat.
It's almost as though you have an animal in liquid form.
They have a really well-adapted body design to move rapidly through a tunnel.
- [Narrator] By filming the ferret in slow motion, Angela can see exactly what the ferret is doing.
(pleasant electronic music) - [Angela] When they're moving around aboveground, they have an arched back posture.
And as they enter a tunnel, they seamlessly lower that posture in their back until their spine is stretched out.
- [Narrator] This flexibility in their spine is due to a unique set of back vertebrae.
In other animals, protrusions known as processes on each segment of the spine stop it from moving too far.
In ferrets, these processes are thinner, creating flexibility and movement.
So their spine can stretch out when they go underground, making their body 30% longer.
This footage shows how easily the ferrets can transition from above to below ground.
But these animals are predators, so what impact does this maneuver have on the ferret's speed?
The black-and-white card helps Angela determine how fast the ferrets are traveling across a set distance.
When the footage is lined up, it reveals something completely unexpected.
The ferret barely loses any speed at all when running underground.
- [Angela] Their shorter-than-average limbs allow them to still be able to move very well, and they aren't restricted in the limb movement in that position.
(intriguing electronic music) - [Narrator] In most carnivores, the legs and body are about the same length.
But in burrowing mustelids like the ferret, their legs are only half the length of their body.
This means they can run in enclosed spaces without tripping over their own limbs.