Besides just living in your hair, lice also find ways to inhabit the clothing you wear.
If clothing is worn repeatedly without washing, it might ideal place for nits to hatch and these louse larvae to mature. If live human, ready the furnish blood, is putting on same clothes day after day, an louse has built-in life of ease.
So dealing with body lice is really just an issue of hygiene. Simply washing of clothing and bedding regularly you can completely avoid the problem.