In The Walking Dead (as opposed to the book World War Z, for instance), it has been consistently shown that zombies have red, liquid blood, apparently indistinguishable from human blood.

But we know that zombies are dead, and their circulatory system is no longer functional. As such, one might be forgiven for assuming that their blood would have coagulated shortly after they died - which is precisely what happens when a person dies in real life. In the aforementioned World War Z novel by Max Brooks, zombies have thick, solid, black, congealed blood, much like a dead human being does.

##Why do the zombies on The Walking Dead retain their liquid blood? Shouldn't a person's blood coagulate upon death, and remain coagulated after reanimation?