How did earthworms become the favorite food of fish, two species that rarely meet in a lifetime?

Earthworms are one of the most basic creatures in the world and live in the soil all year round due to their habits, except for weather factors such as heavy rains. However, due to the life cycle of earthworms, from which many places are born, it can be said that earthworms live in the soil almost all their lives.

In the soil, they feed on decaying leaves and microorganisms, eating food equal to their body weight every day. The way to obtain microorganisms is to eat the soil into their bodies, absorb the microorganisms in the soil, and then expel the undigested soil.

Also, for this reason, earthworms turn the soil when they are active, keeping it breathable, and after eating it, they re-discharge the soil, which will suddenly enrich it with nutrients such as nitrogen, phosphorus, and potassium. These are rare natural fertilizers, and it is for this reason that earthworms were hailed by Darwin as the most valuable creatures on earth.

Through the earthworm's skin breathing, some microvessels on its skin can obtain oxygen directly through gas exchange. To ensure that these microvessels are not clogged by dryness, mucus is secreted from the posterior pores to keep the skin moist. When it rains heavily, the air in the soil will be squeezed out by the rain, resulting in a sudden lack of air, in order not to suffocate and die.

Earthworms will come to the ground, but in summer, heavy rains come and go quickly, and the summer sun is extremely vicious. Those earthworms that run to the ground escape the rain, but they can't escape the roar of the sun. Due to the high temperature and direct sunlight in summer, the mucus on their bodies, which was originally kept moist, was evaporated and covered their whole bodies like a plastic film, causing the earthworms to suffocate and die.

This also shows that earthworms are not only unsuitable for living in water, but also in dry sunlight. The most suitable place for them to live is in the soil, which not only keeps their bodies moist but also is the main source of their food.

By definition, earthworms and fish are originally two creatures that are inferior to cattle and sheep. Both sides may rarely meet once. Normally, the fish can't see the earthworms. But earthworm is the favorite food of fish, also known as the king of fishing because it is loved by many fish.

This is not only curious to many people but also to many biologists. To find out why these scientists also did some experiments.

They found those fish that were bred artificially from birth and simply ate feed without any natural food.

That soft plastic used to do "food" has two shapes, one is irregular plastic scraps, and one is like earthworms made of long strips, from the appearance of certain biological characteristics.

When these two shapes of plastic into the water, a magical scene appeared. Although the plastic is colorless and tasteless, from the results of the experiment, these fish are more interested in that long plastic. They tried to eat these long plastics with their mouths about 10 times more often than those random plastics.

From this experimental data, we can see that fish have a deep desire for creatures with earthworm shapes in their genes. The main reason is that although there are no earthworms in the water, there are some earthworm-shaped creatures. There are many insects whose larvae hatch in the water from an early age and their larvae are of that long shape, as are the leeches that are a food source for fish.

Although fish have never seen earthworms, for this kind of food, fish will naturally take it in their genes as their favorite food. This nature is buried in their genes, just like mammals, sucking breast milk at birth.

Therefore, as a natural preference for fish, there is a special bait on the market which is in the form of a long worm. The teeth of mammals using this bait are hard to bite, let alone fish. This bait requires frequent replacement, is simple and affordable, and is loved by many anglers.

Another reason why fish like to eat earthworms is their earthy flavor. Because earthworms live in the soil all year round, this earthy smell in their bodies is very strong.

As for some omnivorous fish, a large part of their food source is food debris underwater, and underwater, the earthy smell is very strong, so when they smell earthworms, they develop a food affinity and think that this food is delicious.

Thus, the physical sign of the earthworm, combined with its strong earthy smell, makes it favorite fish food.