What causes opioid addiction, and why is it so tough to combat?

Nick Bowman on Instagram: "Move over Arnold it’s Theo time. ****** ex medical study specimen for educational use***** Sirenomelia, also called mermaid syndrome, is a rare congenital deformity in which the legs are fused together, giving the appearance of a mermaid’s tail, hence the nickname. ***first skull is elongated tribal specimen very very very old. -Peruvian."