WHY INSECTS HAVE NO RED BLOOD ?

Vertebrate blood has red blood cells containing hemoglobin, which is a similar molecule to the chlorophyll found in plants, but instead of magnesium, the hemoglobin molecule has an iron atom at the center, which binds with oxygen so that oxygen can be carried by blood to all parts of the body. Insects have a tracheal system, which carries the oxygen through a series of air tube to all part of the body. Insects also have a circulatory system of fluids, similar to our circulatory system. Since their circulatory system lacks hemoglobin, their "blood" is not red.

Insects have blood, but it's not like our blood. Our blood is red because it has hemoglobin, which is used to carry oxygen to where it is needed in the body. Insects get oxygen from a complex system of air tubes that connect to the outside through openings called spiracles. So instead of carrying oxygen, their blood carries nutrients from one part of the body to another. They do bleed when they are hurt, and their blood can clot so they can recover from minor wounds.

Our blood is red because of hemoglobin, some other organisms do have hemoglobin, and some don't which changes the color. Also not all bugs have blood.

Well.... they got some sort of blood going around in there or they wouldn't be alive.

And snails aren't insects.... they're mucus blobs.

Due to the lack of hemoglobin in their blood.