Can only sense what their host senses
<p><b>Mark 9:20 (ESV) </b>
<sup>20 </sup> And they brought the boy to him. And when the spirit saw him, immediately it convulsed the boy, and he fell on the ground and rolled about, foaming at the mouth.
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<p>Notice the demon apparently didn't know it was going to encounter Jesus until its host, the boy, was brought to Jesus.</p>