Do insects have blood?

Yes. But the blood is usually not red like your blood. Insect blood is generally light green, yellow, or colorless. And it doesn’t flow through veins and arteries. The insect’s heart pumps blood through all the empty spaces inside the insect’s body. Slap a mosquito and you may see red blood. But that’s not the blood of the mosquito. It’s your blood—or the blood the mosquito got from another person or from an animal.