Saw a single flea. Do I need to treat?

[JemimaP]

i saw a single flea in a nest box last night when I put the girls to bed. Thought it was a little crawly or a fly but it definitely jumped like a flea. I recently changed their bedding (hemp) and sprayed with poultry shield then dusted with DE before adding clean bedding. I have 3 Pekin bantams who freerange from dawn to dusk.
Do I need to spray with permethrin or wait and see?

 

[AmyJane725]

If you're sure it was a flea I'd go ahead and use the Permethrin. There's never just one flea. Check your birds over thoroughly.