Complex sentence: Harmless to humans, these lizards are known to run from potential threats; a tight rock crevice is sought wherein the Chuckwalla will inflate its body with air in order to entrench itself.
Split into simpler sentences: Harmless to humans, these lizards are known to run from potential threats. When disturbed, the Chuckwalla will gulp air, distend its body and wedge itself into a tight rock crevice.The Chuckwalla will inflate its body with air in order to entrench itself.