Parasitism is the relationship between two living organisms of different species, in which one organism called a parasite obtains its food directly from another living organism called the host. From this interaction, the parasite is benefited, but the host is harmed. The parasite is smaller compared to the host. Ascaris worm living in the intestine of human beings is an example of parasitic interaction, where the worm lives inside the human intestine and develops into an adult. The growth of the worm causes adverse effects on the host such as nausea, vomiting, diarrhoea, loss of appetite, worms in stool, etc. Some species of this worm cause the disease ascariasis.

Camouflage or cryptic colouration is the ability of an animal to blend with its surroundings or background. It is an adaptation of the animals to remain unnoticed by their predators. Some predators also show this adaptation, so their prey won’t see them approaching until it’s too late. Examples of organisms that show camouflage is chameleon, grasshopper, frog, praying mantis, etc.