Many insects are active mainly at night, including moths, fireflies, crickets, mosquitoes, and some beetles. But few are active only after dark throughout their lives: activity depends on species, season, weather, life stage, and what an insect needs to do. What “nocturnal” means for insects Nocturnal animals are most active during the night, while diurnal […]

The insects people describe as coming out every seven years are usually periodical cicadas, but seven years is not the usual interval for the best-known North American broods. Those cicadas spend most of their lives underground and emerge together after a longer, species-specific cycle—most commonly every thirteen or seventeen years. What “every seven years” usually

In physics, forces are commonly grouped as contact forces, which act through physical contact, and noncontact forces, which act across a distance. The fundamental interactions are gravity, electromagnetism, the strong interaction, and the weak interaction; everyday forces such as friction and tension arise from these interactions in more familiar settings. What a force is A

Hydnora africana is a rare, root-parasitic flowering plant native to parts of southern Africa, best known for spending nearly all its life underground and emerging only to flower. It has no ordinary leaves or green stems: instead, it draws water and nutrients from the roots of a host plant, usually a member of the spurge

There is no single reliable lifespan for an “average bird”: birds range from species that may live only a few years to some large parrots and seabirds that can survive for many decades. For a useful general answer, many small wild birds live only a few years on average, while a bird’s species, environment, and

Cellular organelles are specialized structures inside cells that carry out particular jobs, such as making energy, building proteins, or storing genetic information. Examples include the nucleus, mitochondria, ribosomes, endoplasmic reticulum, Golgi apparatus, lysosomes, and—in plant cells—chloroplasts and a large central vacuole. What organelles are and why cells have them An organelle is a distinct cell

No, not all spiders jump. Some species are specialized jumpers, especially jumping spiders, while many others move by walking, running, climbing, or letting silk carry them through the air. Why some spiders jump and others do not Spiders are a remarkably varied group, and their bodies and hunting strategies suit different ways of moving. A

Yes, a roadrunner can fly, but it usually flies only for short distances. It spends most of its time running on the ground, where its long legs and quick movements are better suited to finding food and escaping danger. What Kind of Bird Is a Roadrunner? Roadrunners are ground-dwelling birds in the cuckoo family. The

Orcas are both mammals and whales: they are marine mammals belonging to the toothed-whale group. The word “whale” describes their broader animal group, while “mammal” describes the class of vertebrate they belong to. How the two labels fit together “Mammal” and “whale” are not competing categories. Mammal is a broad biological class that includes animals

Bean plants grow best with abundant direct sunlight: most garden beans need at least six hours of sun a day, and many grow more vigorously with eight or more. Too little light can make plants weak and reduce flowering and pod production, while intense heat can interfere with growth even when sunlight is plentiful. Why