I don't know what a "stick tight flea" is, but those look awfully small for fleas. What happens when you try to wash them off. Does it look like flea dirt? (is it reddish in water?) You could certainly try DE, but be careful using it around his face...don't let her inhale it. And, yes, I would think if it's anything living, coconut oil or mineral oil would keep it from surviving.
Thanks! Stick tight fleas also known as hen fleas imbead their heads into their hosts unlike normal fleas where they jump around, these do not. She had them last year and my vet prescribed horrible advantage for her although it did rid her of the bug but left her lethargic and with diarrhea. Never again! I used coconut oil last night and today I don't see any fleas on her. I think