Related Clues:
- NOFX song they wrote about their dog?
- Castledoor "The Birds and the ___"
- Worrisome subject of some school letters to parents
- Cause of much head-scratching
- Vermin that cause head-scratching
- Beagle bane
- Bugs that bring "ughs"
- Heady pests?
- Nasty infestation
- Victims of some pet collars
- Boxer's concern, maybe
- Minute parasites
- Pests at kennels
- Wingless bloodsuckers
- Fully grown nits