They are some of the heaviest animals on the planet, but for their size, rhinos have quite small feet.
It's a mystery that's puzzled experts for years - just how do these wildlife-whoppers manage to walk on their tiny toes?
Now, using some clever new technology, experts are hoping to find out.
Scientists have trained the rhinos at Colchester Zoo to walk across a special track that measures the pressure they put on their feet.
But it's not been easy - keepers have had to gently encourage the animals to walk through the small space.
One of the big mysteries that they hope to solve is the difference between how rhinos and elephants walk.
Elephants have five toes, and even though rhinos can weigh up to two tons they only have three tootsies.
This means lots of pressure is put on rhinos feet - which can lead to problems.
Vets in zoos often have to treat foot problems for the animals kept in captivity.
It's hoped that by being able to measure just how the giant animals spread their weight, they can do more to prevent problems in the future.