Spike's not a fan of being stroked. If they're happy the quils fall flat against the back and they're not difficult to handle. If they're unhappy with you then they'll frown, covering the eyes with quils, and the rest of the quils stand up rigid. At this point you *really* don't want to touch him, since if you do he'll jump and if he makes contact it ******* hurts!
If you upend him, he'll roll into a ball and frown. If you wait he'll slowly come out of the ball which is when you can get the cute pics.
Here's a pic of him in a mood, coming out of a ball:
Generally he's happy enough though and will let you handle him. Just don't stroke his back