Cockroaches are nocturnal animals and with a few exceptions, they avoid the light of day and prefer to be active at night time when they can carry out their business undetected.
The only species of cockroach that are not avoidant light are the Asian cockroaches which are in fact attracted to light. The American cockroach and German cockroach will scurry away and attempt to hide at the first sign of light.
Cockroaches are nocturnal and that they are generally only active for a few hours during the night time when they are in search of food and water.
If there is a large population of cockroaches or there is a short supply of food and water, it may force the roaches to become more active during the daytime, although that is not their first preference.
So, if you see cockroaches in your home during the daytime, there are likely thousands of roaches active and infesting your house.