Human

Human is the life state a Sim is born or created with. It can also be considered "normal" i.e. lacking a life state. Unlike the other life states, being human does not offer any pros or cons, although, that in itself, can be seen as a pro or con.

Compatibility
Unlike the other life states, if a human turns to another life state he or she will cease to be human. For example, if a vampire is attacked by a werewolf, the vampire will remain a vampire but also become a werewolf. However, if a human is attacked by a vampire the human will cease to be a human and become a full vampire.

Thus it is impossible to make human-hybrids, except in the case of aliens, but this is caused by genetics, rather than a "true" life state as in the case of a werewolf's savage or a vampire's bite neck.

Human Species
In addition to being a life state human may also refer to the human species. For example: A witch is a human who possesses the knowledge of using magical abilities. A werewolf is a human during the day. A plantsim is not a human, nor is a bigfoot. Vampires are arguably human. Some consider them to be human while some do not. Zombies are considered to be not human but they are really just a living dead human.

Biology
Every Human Has A skin Colour Either Brown or Wite In Sims and sims 2 While In sims 3 you cant have ailiens but you can make the skin colour blue green and red Also if a sim is a ghost that is in the family he does NOT count as a human Ghosts Are DEAD they Have Died
 * 1) Here you can see Ghosts
 * 2) Here you can see death

Trivia

 * In The Sims universe, humans appear to be the same species as in real life.
 * Humans are the only Life state possible to make in Create-A-Sim (unless using boolprop testingcheatsenabled in which alien and mannequin skin are available.)
 * Unlike the rest of animal kingdom, Humans (and potentially others) have the unique ability to create works of technology.
 * It is unknown if other life states are related to Humans as a species.