fleas
They look like little fleas
No they are smaller and whitish clear, fleas are larger and black.
Maybe you're referring to gn Springtails maybe.....
http://lubbock.tamu.edu/ipm/AgWeb/photo_galleries/photoother/deerfly.gif
Yes you can, and they jump and bite OUCH! they look like little black or brown things.
Yes, birds can get fleas. It's called bird fleas look it up. They're pretty rare though.
No. Fleas themselves cannot have fleas, but they can have these things called "mites".
Gnats do not jump, they fly. However, if you have insects that look like gnats and jump, you may have fleas.
weevils
I've recently discovered an infestation of these critters in my bathroom, and will soon be massacuring them. All i can tell you is that they are of the order Syphonoptera (like fleas), but are definitely not cat, dog, or human fleas. i recommend a fogger like Raid, and manual spraying. Good luck! p.s. they bite!
Pets are a convenient source of food for fleas.