
Louse
Plural Form
The plural of 'louse' is 'lice.' Remember, just changing 's' to 'z' doesn't make it plural. 
Physical Context
'Louse' is often used when talking about personal hygiene issues related to hair or skin. 
Specific Species
'Louse' applies to several species, but 'head louse' is most common in conversations about children. 