A common quandry in parasitology is identification of different types of parasites.
When it comes to the subject of lice, there are some happy coincidences which make life easier.
For Sucking Lice, simply remember the initial letter ‘S‘:
They Suck
They have Small heads
They move Slowly
They have Sideways or forward pointing antennae
They are around 5mm in size
(ok, stretching it but the number ‘5’ looks a wee bit like an ‘S’)
For Biting Lice, the letter ‘B‘ is all important:
They Bite
They have Big heads
They Move Bloomin’ quick (ahem!)
They have Backward pointing antennae
They are around 3mm in size
(if you draw a vertical line through the start of the number ‘3’, it becomes a ‘B’)