The Talmud describes the Shedim as possessing some traits of angels, and some traits of humans:
In three ways they are like ministering angels: They have wings like ministering angels; and they fly from one end of the world to the other like ministering angels; and they know what will be in the future like ministering angels. And in three ways they are similar to humans: They eat and drink like humans; they multiply like humans; and they die like humans.
They can cause sickness and misfortune, follow the dead and fly around graves.
There are many things that one is admonished not to do in order to avoid invoking shedim, such as whistling or even saying the word "shedim".
The shedim are not always seen as malicious creatures and are also considered to be helpful to humans. They are said to be even able to live according to the Torah, like Asmodeus.
