If I did it to anything that made noise while torturing I'd throw up. bugs stay dead silent, show no expressions of pain, just squirm and twitch. Imagine doing this to a frog and hearing its little squeals. that thought makes my stomach feel sick.
there is an indescribable pleasure I get from putting a bug on tape and covering it in isopropyl and watching its movements get slightly slower, till that last little twitch before fully relaxing.