A coon dog and a tick, an oak tree with moss on the north side, a termite and its internal bacteria and a shark with small fish that eat the excess flesh the pieces between the teeth they all have one thing in common: symbiosis. Defined as the interdependence of organisms, symbiosis is the basis of the relationship between George and Lennie in John Steinbeck's “Of Mice and Men.” One type of symbiosis helps both parties while another type involves one organism being harmed by the exchange. The dog is injured by the tick while the termites and bacteria benefit from each other's presence. These types of symbiosis can occur in humans and are evident in “Of Mice and Men.” Both types of symbiosis exist between George and Lennie in the novel. George and Lennie's physical symbiosis is beneficial to Lennie but harmful to George. Although George hurt Lennie, Lennie now needs George to save him from trouble. Lennie also profits because he needs a person to tell him what to do. “He can't think of anything to do on his own, but he sure can take orders” (39). Lennie is "a very good worker" (22) and is able to "whip up a four hundred pound bale" (22), but is likely to get into trouble without George's protective influence. George likes Lennie but would be better off without him because "you (Lennie) can't keep a job and you lose me every job I get" (11). Lennie hinders George while George helps Lennie. The emotional symbiosis between George and Lennie helps every man. Lennie's attachment to George is most strongly visible when Crooks suggests that George will not return. Lennie is almost hysterical and his fear does not subside quickly. George prefers to feign dislike for Lennie by looking Lennie in the face: "I could get along so easily and so well if I didn't have you after me" (7). When pressed, George reveals his true feelings for Lennie. “I want you to stay with me Lennie” (13). They stay together because “It's a lot easier to hang out with a guy you know” (35). Both men need and value their strong emotional relationship. George and Lennie need each other to realize their dream of a farm of their own with rabbits to look after. Lennie couldn't take care of his rabbits or even survive without George.