Science

No. Eastern indigo snakes are typically docile; they usually try to crawl away when disturbed and rarely bite people.

Yes. Humans are mammals, and all living mammals are synapsids—the clade defined in part by a single temporal skull opening.

Yes. Hippos are mammals in subphylum Vertebrata, so they have a backbone.

REM sleep is the rapid-eye-movement phase when brain activity is wake-like, dreaming usually occurs, and muscles go limp.

Yes. High-density lipoproteins (HDL) are often called “good” cholesterol because they absorb cholesterol in the blood and carry it back to the liver, which then flushes it from the body. According to the U.S. Centers for Disease Control and Prevention (CDC), higher HDL levels can lower risk for heart disease and stroke, while high LDL … Read more

Their barbed hairs can irritate skin, but they are not classically poisonous and systemic reactions are not known.

No. A habitat is where an organism lives; an ecosystem is the web of living and nonliving interactions in an area.

Gray wolves (Canis lupus) are not rare at the global species level. Conservation references summarizing the IUCN Red List treat the grey wolf as Least Concern because the species remains widespread, with worldwide population estimates often placed in the hundreds of thousands of individuals. Regionally, the picture is different: wolves were wiped out across much … Read more

Shortening days and cooling temperatures stop chlorophyll production, revealing yellow carotenoids and often red anthocyanins before leaves drop.

Yes. All living great ape species are classified as Endangered or Critically Endangered on the IUCN Red List.