Before he could test the spell on it, Cam held the gummy worm and well... he wanted one NOW. Not later. NOW. He wondered if he could just eat a tiny piece of it and pretend nothing really happened, but there were too many people that he could've gotten caught. Putting it back on the desk, he held his wand up hiiiiigh and then pointed it straight at the edible candy worm. He would have done better with a snail because he kept getting distracted... by its heavenly goodness. He tried to do the wand movement again just to make sure that he had done it right.

"Evanescoooo." Wait, no, bleh, he forgot most spells had to be precise. But he watched the worm to see if he had any luck. He poked it. Hmm. Nothing. Not even a piece of it disappeared. "EVAN-ESCO." This time he put a little bit more force in his words and wand movement. OOOOOOOH. It wiggled. WIGGLED, I TELL YA. "Iiiit wiggleddd!"

Wiggling > Vanishing when it comes to worms.