Coenobita clypeatus (Hermit Crab) (image) Max Planck Institute for Chemical Ecology Caption An adult Coenobita clypeatus hermit crab uses a discarded snail shell for protection: both pairs of antennae are clearly visible. Olfactory receptors are located on the inner pair of antennae, which are bent upwards. The crabs' sense of smell is still underdeveloped in comparison to insect olfaction. Credit Max Planck Institute for Chemical Ecology/ Krång Usage Restrictions None Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.