Prisons can be considered "total institutions" that develop their own social structures and values. In prisons, there is an informal inmate social world that exists alongside the formal rules imposed by staff. Over time, inmates may become "prisonized" and accept the criminal social norms. Prison subcultures form in response to the deprivations of prison life. Sexual assault in prison is often about asserting power rather than sexual desire. Female inmates face additional hardships of being separated from their children and have different pathways into the criminal justice system. Prisons struggle with ensuring humane conditions and protecting inmates' rights while maintaining security.