Book 4, Question 130
Why Do Some Animals See Well at Night?
Night hunters pack extra tools into their eyes. A wide pupil lets in more light, and special cells called rods catch dim light. Many also have a mirror layer that gives light a second chance to be seen.
From the book
Page from A Million Whys Book 4
More fun facts
- Night animals face a big problem: gathering enough light to see.
- Their retinas are packed with rod cells, which are more sensitive to light than the cone cells that see color.
- In night mammals like mice and cats, rod cells pack their DNA in a special way that turns each cell's center into a tiny light-collecting lens.
- Day animals such as pigs and squirrels pack their DNA the opposite way.
- In the dark, the European common frog can still tell green from blue.
- A sweat bee that flies at twilight can recognize its own nest by stripes placed near the entrance.
Sources: National Geographic, Scientific American
Questions kids ask
Can any animals see colors at night?
Some can. Scientists found that the European common frog can tell green from blue even in the dark.