Comasphaeridium molliculum belongs to the Acritarchs, an artificial group of organic fossil remains. Image is under CC BY-SA of Museum of Geology, University of Tartu (http://1url.cz/U2l1).
Flea (Leptopsylla) - jumping blood sucker! Image is under CC BY of Zoological Research Museum Koenig (http://1url.cz/AHFl)
Polutry Louse - this small creature nourishes with feathers, skin excretions or blood of polutry. Image is under CC BY of Collections / Zoological Research Museum Koenig (http://1url.cz/AHFl).