An otter family lives together: mum, dad, this year's pups and last year's pups, all in one group of around 5 to 10. They travel as a pack, splashing in single file along canals and rivers. People in Singapore have given some of the most famous families their own names, like the Bishan family and the Marina family.
Otters can hold their breath for about 4 minutes and dive several metres down to chase fish. They eat lots of fish a day - they have to, because they are so active. After hunting, they pull themselves up onto a sunny patch of grass to rest and 'groom' their fur dry.
Sometimes a whole otter family will decide to cross a busy road. Traffic stops, people pull out phones, and the pups follow the grown-ups across in a wobbly line. The otters take their time. The cars wait. Then everyone moves on.
Singapore is one of the only big cities in the world where wild otters live this comfortably. Scientists think it works because the rivers and ponds were cleaned up over the years and stocked with fish. Once the water was healthy, the otters came back on their own.