What does the idiom mean to scratch the surface? What is the purpose of the dragonfly's tail to order water?

Dragonfly is a typical incomplete metamorphosis insect, which does not need to go through the process of pupation when it changes from juvenile to adult. Dragonflies fly on the surface of the water, with the tip of the tail close to the surface of the water, and point the water with the tip of the tail at 1.1, as the saying goes, "dragonfly scratches the surface". What does it mean to scratch the surface? What is the purpose?

Dragonflies, invertebrates, arthropod phylum, Insecta, winged subclass, Odonata, Heteroptera, divided into dragonidae and fly families.

Generally large, long and narrow wings, membranous, reticular wing veins are very clear. Extremely sensitive vision, 3 single eyes; 1 pair of antennae, thin and short; chewable mouthparts. The abdomen is slender, flat or cylindrical, with anal appendages at the end. The foot is thin and weak, with hooks on it, and can catch pests when flying in the air. Larvae (nymphs) develop in water and breathe through rectal trachea Gill in water. Generally, it takes more than 11 times to molt, and it takes 2 or more years to climb out of the water surface along the aquatic plants, and then finally molt and feather into adults. Young worms can prey on wigglers or other small animals in the water, and sometimes the same kind also eat each other. Adults usually fly in ponds or rivers to prey on flying insects. In addition to a large number of insects that are harmful to people, such as mosquitoes and flies, some can also prey on butterflies, moths and bees, which are actually beneficial insects. There are more than 5000 known species of dragonflies.

The meaning of scratching the surface

"dragonfly scratching the water" refers to the action of a dragonfly touching the surface of the water with its tail when it is flying. It means doing something superficial and not going deep. It also describes a light kiss. Both "scratching the surface" and "taking a quick look at the flowers" can be compared to work or experience life is not very in-depth, often can be used. However, the emphasis is on the "point", which refers to doing things "at a glance", "not in-depth, not persistent", while "looking at the flowers" focuses on "watching".

What is the purpose of scratching the surface?

Dragonflies lay eggs directly into the water or on aquatic plants. The larvae hatched by the eggs are called water bugs. The puddle often sticks out its lower lip with a hook to catch small animals in the water for a living. Shuihu is a swimming expert, it uses the jet type, as long as the abdomen is compressed, the water will be sprayed back, the body naturally forward, the speed is very fast. Breathe through the rectum, trachea and Gill. When the water boat grows up, it climbs onto a branch or stone protruding from the water and feathers into an adult dragonfly like a dragon in the air.

An allusion to the surface.

When Emperor Suzong Li Heng, du Fu became an official of Ba Pin Yan. He was alienated by Li Heng because he spoke for a minister who should not have been accused. He was very depressed and went to Qujiang to write poems to relax himself. Among them, "two songs of Qujiang" wrote, "the butterfly is deeply seen by the butterfly, and the dragonfly flies with a little water." It is said that the spring light is in circulation, and there is no contradiction between admiration and appreciation for the time being. "

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