Stop what you're doing right now and check the tag on your shirt. Only 80% cotton? Uh-oh, 10% wool? Kilayim. Eternal Hellfire for you.
Check your garden. Have you inter-cropped plant varieties? Mixed seeds of two varieties of Lettuce? Kilayim. Eternal Hellfire awaits.
Check your fruit trees. Grafted rootstock? Kilayim. Eternal Hellfire.