Gorillas can walk on two legs using knuckle-walking. Chimpanzees can walk on two legs for over half a mile. Gibbons walk more on two legs than any other non-human primate
Alligators are smaller, black/gray with cream underside, and have U-shaped snouts. Crocodiles are larger, green/brown with V-shaped snouts, and can reach 15-17 feet. Both have tough skin, long tails, stubby legs, and large teeth
Symbiosis involves two organisms living together in close physical association. Mutualism benefits both organisms, like cats and dogs for companionship. Commensalism benefits one organism without harming the other. Parasitism benefits one organism while harming the other. Competition occurs when organisms compete for prey or territory
Rats are natural students with human-like brain structure and problem-solving abilities. Pigeons can recognize all 26 English letters and show complex self-awareness. Crows are tool-using non-primates with largest avian brains. Pigs are highly trainable with 20 different communication sounds. Octopuses use high-order planning and can disguise themselves as rocks
Blue whale is world's largest mammal at 200 tons and 100 feet long. African elephant is largest land mammal at 7 tons. Killer whales (orcas) are largest dolphins at 6-7 tons. Southern elephant seal is largest terrestrial meat-eating mammal at 3-4 tons
Frogs have long hind legs and webbed feet with sticky pads. Toads have shorter hind legs and unwebbed feet. Frogs are slender and athletic, while toads are shorter and stubbier. Frog skin is smooth and rubbery, while toad skin is bumpy. Frogs are generally lighter green, while toads are darker olive-green