Most bots are benign and used to keep a particular channel open.
Often they are used for channel maintenance, such as kicking users for rude language, to stop flooding in a channel, or remove offensive nicks. Other bots have a specific purpose, such as helping to run a game or serving virtual drinks. A few can be abusive bots such as war or takeover bots. Almost all IRC Nets and servers do not allow war or takeover bots. Attempting to run such bots is a quick way to get k-lined from a network.