yöeläimiä

Yöeläimiä, Finnish for "nocturnal animals," refers to creatures that are primarily active during the night. This behavioral pattern is an adaptation to avoid predators, escape daytime heat, or take advantage of resources that are more readily available after dark. Many nocturnal animals possess specialized senses to navigate and hunt in low light conditions.

Common adaptations include enhanced hearing, a keen sense of smell, and superior night vision. Eyes of nocturnal animals often have a higher proportion of rods, which are photoreceptor cells sensitive to dim light, and some species may have a tapetum lucidum, a reflective layer behind the retina that amplifies available light. Examples of nocturnal animals are widespread across various animal groups.

In the mammalian kingdom, bats are famously nocturnal, using echolocation to find insects and navigate. Many rodents, such as mice and rats, are also primarily active at night. Several species of cats, like the domestic cat and larger wild felines, exhibit nocturnal or crepuscular (active at dawn and dusk) behaviors. Owls are a classic example of nocturnal birds, with their silent flight and exceptional vision enabling them to hunt effectively in darkness. Insects like moths are well-known for their nighttime activity, often attracted to light sources. Many amphibians and reptiles also display nocturnal tendencies to avoid the sun's intensity and to hunt prey that emerges after sunset.