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Caffeine

Caffeine, sometimes called theine when found in tea, is a xanthine alkaloid found in the leaves and beans of the coffee tree, in tea, yerba mate, guarana berries, and in small quantities in cocoa, the kola nut and the Yaupon holly. In plants, caffeine acts as a natural pesticide that paralyzes and kills many insects feeding upon them. Caffeine is a central nervous system (CNS) stimulant, having the effect of warding off drowsiness and restoring alertness. Caffeine-containing beverages, such as coffee and tea, enjoy great popularity, making caffeine the world's most popular psychoactive substance.

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Plants & Animals News

February 27, 2026

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Deep in the Congo Basin, vast peatlands quietly store enormous amounts of Earth’s carbon — but new research suggests this ancient vault may be leaking. Scientists studying Africa’s largest ...
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Flea and tick medications trusted by pet owners worldwide may have an unexpected environmental cost. Scientists found that active ingredients from isoxazoline treatments pass into pet feces, exposing dung-feeding insects to toxic chemicals. These ...
Deep inside a Romanian ice cave, locked away in a 5,000-year-old layer of ice, scientists have uncovered a bacterium with a startling secret: it’s resistant to many modern antibiotics. Despite predating the antibiotic era, this cold-loving microbe ...
As the planet warms, many expected ecosystems to change faster and faster. Instead, a massive global study shows that species turnover has slowed by about one-third since the 1970s. Nature’s constant reshuffling appears to be driven more by ...
Researchers investigating crops grown in soil contaminated by the 2015 mining disaster in Brazil discovered that toxic metals are moving from the earth into edible plants. Bananas, cassava, and cocoa were found to absorb elements like lead and ...
Even Antarctica’s toughest native insect can’t escape the reach of plastic pollution. Scientists have discovered that Belgica antarctica — a tiny, rice-sized midge and the southernmost insect on Earth — is already ingesting microplastics in ...
A new study shows that dogs and cats may be helping an invasive flatworm spread. Researchers analyzing over a decade of reports discovered the worm attached to pet fur. Its sticky mucus and ability to reproduce alone make it highly adaptable. Pets ...
Scientists are launching an ambitious global effort to map the “human exposome” — the lifelong mix of environmental and chemical exposures that drive most diseases. Backed by new partnerships with governments, UNESCO, and international science ...
A new scientific review challenges the headline-grabbing claim that Yellowstone’s returning wolves triggered one of the strongest trophic cascades on Earth. Researchers found that the reported 1,500% surge in willow growth was based on circular ...

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