What does comfort latching means at night?

it is your baby sucking for comfort, using you as a human pacifier. they're not hungry but they want to latch on. http://kellymom.com/bf/normal/comfortnursing/ has a bit more info for you here.

Means your baby is nursing herself to sleep rather than nursing for hunger. Means you are doing double duty - your breasts are not just for nutrition but also used as a sleep prop.

Means that baby is using you as a pacifier to soothe himself at night.

Comfort latching means Human Pacifier