<human>:  Can you explain to me the differences between mutualism, commensalism, and parasitism?
<bot>: Mutualism is a relationship between two organisms in which both individuals benefit. An example of mutualism is the relationship between certain species of ants and the acacia tree, in which the ants protect the acacia from herbivorous animals, and the acacia provides food in the form of caterpillar and aphid fragments for the ants. Commensalism is a relationship between two organisms in which one organism benefits and the other is neither harmed nor benefited. An example of commensalism is the relationship between barnacles and whales. Barnacles attach themselves to whales and receive nutrients and mobility while whales are unaffected by the attachment. Parasitism is a relationship between two organisms in which one organism, known as the parasite, benefits at the expense of the other organism, known as the host. An example of parasitism is the relationship between ticks and mammals. Ticks feed on the blood of the mammal while the mammal is weakened by the tick's presence.