The more you know

Stars look tiny and twinkle because we see them from far away through Earth’s atmosphere, which bends their light. The sun looks bigger because it’s closer to us. Stars vary in size, with some much larger than the sun. Planets can also appear to twinkle as they reflect sunlight. For the best stargazing, head somewhere dark and open. Apps can help identify stars, and local events offer chances to explore the night sky.

Cicadas are loud insects with unique anatomy. They have an exoskeleton, six legs, four wings, antennae, compound eyes, and a beak for sipping plant juices. Males make sound using tymbals—ribbed organs that click when flexed. Air sacs amplify the sound, which can be as loud as a lawnmower. They call to attract mates, express distress, or say “leave me alone.” Despite no lungs or vocal cords, their body design makes them some of the loudest insects on Earth.

Plants may seem picky, but many survive in tough places like sidewalk cracks. Tiny roots find microscopic gaps in concrete, seeking water and soil. As roots grow, they widen cracks, letting in more water and helping the plant thrive. These hardy plants create mini-ecosystems for insects and pollinators. You can even watch root growth at home using seeds in a clear bag.

Earth is home to millions of species and is about 71% water. It’s not a perfect sphere, constantly changing shape due to tectonic activity and melting glaciers. Formed over 4.5 billion years ago, Earth won’t last forever as the sun will eventually die. The highest point is Mount Everest, the lowest is Challenger Deep. Earth’s name is unique among planets and its mantle is semi-solid, driving geological activity. Climate change threatens its ability to support life.

Birds sing early in the morning in what’s called the dawn chorus, mostly to attract mates and claim territory. Mornings are quieter and safer, helping their songs carry farther. Studies show birds improve their singing as the day goes on, suggesting morning songs are like vocal warmups. While male birds do most of the singing, some females sing too. In cities, the chorus may start earlier due to artificial light. Spring and summer are peak singing seasons.

Owls swallow prey whole and later cough up indigestible parts like bones and fur in a compact pellet. This process is called casting. Owl pellets are often dissected in science class because they contain complete bones and are larger than those from other birds. Many birds cast pellets, but owls are the most well-known. Wild pellets should not be handled due to germs. Pellets show how different animals digest food and offer clues about what they eat.

Some birds live in Illinois year-round, but many migrate to warmer places for food. In spring, eastern phoebes, barn swallows and great blue herons return. Phoebes and swallows eat insects, so they leave in winter. Herons migrate because their prey hides or slows down in cold water. Watch for these birds nesting in local parks and preserves. You might spot a returning migrator or even hear its unique call.

American and European robins share orange breasts, similar diets, and habitats, but they aren’t closely related. American robins are larger, darker, and belong to the thrush family, while European robins are smaller flycatchers. Both species eat insects, fruits, and worms and are common in parks and yards across their ranges. Despite bird declines overall, robin populations are growing, and both have migratory and non-migratory groups based on climate.