1. birds
1.1. flight
1.2. pigeons
1.2.1. beaks have iron, like a compass
1.3. kingfisher bird
1.3.1. shaping trains like their beaks to get to maximum speed
2. animals
2.1. termite mounds
2.1.1. maintain a constant internal temperature due to their structure and interaction with the local environment, rather than use of expensive, external energy sources. Several factors allow mounds to stay 87° F inside--the optimum temperature for the fungi these termites cultivate--while the temperature ranges from 35° - 104° outside
2.2. sharkskin
2.2.1. swimsuit
2.2.1.1. made up of countless overlapping scales called dermal denticles (or "little skin teeth"). The denticles have grooves running down their length in alignment with water flow. These grooves disrupt the formation of eddies, or turbulent swirls of slower water, making the water pass by faster. The rough shape also discourages parasitic growth such as algae and barnacles.
2.3. humpback whale
2.3.1. channel flow and increase aerodynamic efficiency due to tubercles or bumps- wind energy
3. senses
3.1. rock crab
3.1.1. very complex structure for survival- hard exoskeleton, a smooth oval or fan-shaped carapace with a rounded front border, antennae used for taste and smell, and two movable eyestalks located at the front of the shell. Between the eyestalks are three spines and nine smooth spines run along the outside edge of the carapace.
3.2. narwhal
3.2.1. tusks of male narwhals may detect chemicals related to ice formation, salinity, or prey using a vast network of fluid-filled tubules connected to the tusk's central nerve
4. cold
4.1. bear hibernation
4.1.1. a temporary sleep during cold, winter months- a state of self-induced reduction in body temperature and metabolic rate to conserve energy
4.2. water bear and brine shrimp
4.2.1. can survive dehydration