Answer:

lice

Answer	Crossword Clue
LICE	Parasitic insects
LICE	External parasites
LICE	Hair-y pests

LICE	Plant ... (aphids)
LICE	Plant .. (aphids)
LICE	Small parasites
LICE	Cooties
LICE	They cause head scratching
LICE	Certain shampoo target
LICE	Targets of a pediculicide
LICE	Aphids

LICE	Obnoxious types
LICE	Some parasites
LICE	Wingless parasites
LICE	Nit layers
LICE	Fully grown nits
LICE	Head case?
LICE	Little suckers
LICE	Tiny parasites

LICE	Bothersome parasites
LICE	Layers of nits
LICE	Beggar's-... (sticky seeds)
LICE	Dog bane
LICE	Wingless suckers
LICE	Head hunters?
LICE	Parasitical insects
LICE	Adult nits

LICE	Grown nits
LICE	Nasty insects
LICE	Tiny biting insects
LICE	Tiny insects
LICE	Nitpicker's target
LICE	Scalp misery
LICE	A pox on your locks
LICE	Cause of some head scratching?

LICE	Subject of some notes sent home to parents by the school nurse
LICE	Target of a head hunter
LICE	Canine problems
LICE	Nit-laying nuisances
LICE	Wingless bloodsuckers