Hello~ Can you help me say this naturally please?
A: Hey, why don't you turn the light off?
B: ⓐI keep the light on intentionally,
ⓑI keep the light on on purpose,
if I turn the light off cockroaches come out, you know.
A: Oh, yea, they usually come out when it darks.
They usually come out when it gets dark.(All the phrases in bold are fine.)