Here's why:
* The moon is always there: The moon orbits the Earth constantly.
* Light from the sun: The reason we see the moon at night is because the sun is shining on it, and the reflected sunlight is what we see.
* Daytime brightness: During the day, the sun is so bright that it's hard to see the faint light of the moon.
However, if you know where to look and have clear skies, you can definitely spot the moon during the day!