These larvae account for the majority of the small invertebrates in freshwater environments serving as prey for many other insects and food for most species of fish including the Trout. They do not come and go like some insect life and are usually present throughout the year. The sunshine can be a good stimulant on the Bloodworm and gets them a bit more active and moving out of the silt and mud on the waters bottom higher up in the water, so on a cold winters day when the sun is blinking through the clouds it is always worth a dabble with a bloodworm. The leggy Bloodworm is another good choice at any time of the year