Dolphins are one of the few animals other than humans known to mate for reasons other than reproduction and especially male Bottlenose Dolphins are known to engage in sexual acts with other dolphin species, which is not always consensual, though the Bottlenose may also be submissive in such encounters. Occasionally, dolphins will also show sexual behaviour towards humans.

If you eat a polar bear liver, you will die of vitamin A poisoning. As a carnivore which feeds largely upon fish-eating carnivores, the polar bear ingests large amounts of vitamin A, which is stored in its liver; in the past, humans have been poisoned by eating the livers of polar bears.

The shortest binomial name of a species is "Ia io", which belongs to the Great Evening Bat.

The common guinea pig was first domesticated in about 2000 BC by the people living in the Andes mountains, as a food source. To this day, they continue to be a major part of the diet in Peru and Bolivia, where they are an important source of protein and a mainstay of Andean folk medicine. Peruvians consume an estimated 65 million Guinea pigs each year, and the animal is so entrenched in the culture that one famous painting of the Last Supper in the main cathedral in Cusco, Peru shows Christ and the twelve disciples dining on guinea pig.

Although there are approximately 200 million starlings in North America, they are all descendants of approximately 60 birds released in Central Park, New York, by Eugene Schieffelin, who headed an acclimatization society trying to introduce to North America every bird species mentioned in the works of William Shakespeare.