Henry has trouble with head lice but explains that his pet Quonkka Basil gets it ten times worse with fleas. In fact, the Quonkka is bedeviled by giant fleas that nest in a 20 ft high cocoon hanging from the eaves of the house. The kids help Basil get rid of the flea problem but when they try to feed Basil his special Marsupial Flea Tablets, he is not a willing participant.