慣習vs.習慣 : What's the Difference?

習慣: habit.

It's a routine thing to do by more individuals, particularly in a way.

For example:

私たちはイヌを食べる習慣はないです。

We don't have the habit of eating dogs.

慣習: custom. 

It's a cultural thing to do by the community or country.

For example:

慣習を破る。 Break custom.