Allah says in the Qur'an, Iblees and his ilk see you the way you cannot see "him."
Says the Qur'an:
Min Hayithu Laa Tarawunahoo.
Rasulullah, Sallallahu Alaihi wa Sallam, says: Shaitan races through your veins like blood.
Says the Hadith:
As a result, part of the challenge of being a Muslim is to be able to recognize Iblees and his Ilk -- Shaitan -- in all their disguises.
The Qur'an and Hadeeth both make it clear that Shayateen -- plural for Shaitan -- come in the form Jinn as well as humans.
So, there are two kinds of Shayaateen: Jinn and Ins.
Ins is human beings whom God created with clay. Jinn is a creature God made with fire.
Iblees, the Shaitan, was a Jinn, says the Qur'an. And he chose to disobey God's command.
This is how the Qur'an puts it:
Kaana Minal Jinni!
Fa-Fasaqa An Amri Rabbihi!
And the job of the Believers -- Mu'mins, Muslims -- everywhere is to be able to identify both kinds of Shayaateen in their midst in a timely manner and deal with them both effectively.