Otters are nocturnal and rarely seen during the day. If they are seen, they are usually swimming with only the head above the water.
Otter droppings (spraints) smell sweet, like fresh hay or jasmine tea. They
contain fish bones and occasionally feathers and fur. Scats are used to mark territories and are usually places on prominent places such as rocks or ledges.
Spraints can often be found on ledges under bridges (when they have not been washed away by high water levels). The photograph shows the disassembled contents of a spraint.
Look in soft mud for otter tracks. Although otters have five toes, usually only four are seen on a footprint. Good otter prints will show an impression of the webbing between the toes.