WHAT READERS WONDER MOST

Rare can mean a small population, a tiny range, or simply an animal that lives where people rarely go. The IUCN Red List measures extinction risk with set criteria; a species that is rarely seen may still be common, or may be listed as Data Deficient because nobody can count it.

Yes. In 2007, on the FOTON-M3 mission, dried tardigrades were exposed to the vacuum of space, and many survived and later reproduced. Survival dropped sharply when they were also exposed to full solar ultraviolet radiation. They survive by drying out into a dormant state, not by being active in space.

Yes. Bacteria around hydrothermal vents and in sealed caves such as Movile Cave in Romania make food from chemicals like hydrogen sulphide. This chemosynthesis supports tube worms, crabs, snails and cave invertebrates. See the ecosystem notes

Venus flytraps measurably count trigger-hair touches through electrical signals before closing and digesting. Whether plants learn is debated: a 2014 study on Mimosa pudica suggested habituation, but its interpretation is disputed and not widely replicated.

Isolation lets populations evolve separately for long periods with few competitors or predators. That produces endemic species found nowhere else, such as the plants of Socotra, but also makes them vulnerable when rats, cats or goats arrive.

Roughly two million species have been formally described, and thousands more are added each year, mostly insects, fungi and marine invertebrates. Many come from deep-sea expeditions, remote forests and from re-examining museum collections with DNA tools.

Often yes, if you buy captive-bred animals or nursery-propagated plants and check your local laws. Never take them from the wild. Taking wild Venus flytraps in North Carolina has been a felony since 2014.

Both are visited with licensed local guides, but conditions are extreme: caustic water, intense heat and, at Dallol, toxic gases. Follow guides and current official travel advice. This notebook is not travel or safety advice.

We rely on peer-reviewed studies, IUCN assessments, natural history museums and official park and conservation sources. Numbers carry a date where they change, and popular claims we cannot verify are labelled as rumour checks.