First of all, the insects in mountain spring water may be Daphnia. Daphnia is a common aquatic insects. Its body is rectangular, about 1-2 cm long, usually light green or yellow. When they swim in the water, they will twist their bodies and present a shape similar to a slender yellow bug. If Daphnia moves in cold water, their bodies may be slimmer and the length can reach more than ten centimeters.
In addition, insects in mountain spring water may also be water insects. Water earthworm is an annelid, with a cylindrical body and a length ranging from several centimeters to dozens of centimeters. They usually live in fresh water and like to make holes in the soil, so they may also exist in the soil of mountain springs.
Whether it is Daphnia or earthworm, they are all freshwater creatures and have no harm to human body. If you are worried about water quality, it is recommended not to drink raw water. You'd better boil the water before drinking. At the same time, if a large number of insects or other impurities are found in mountain spring water, it is recommended not to use this water source.