Answer: Hymenolepis diminuta, the rat tapeworm. Humans become infected when accidentally ingesting infected arthropods.
H. diminuta eggs can be differentiated from the similar-appearing eggs of Hymenolepis nana by their larger size (70-80 micrometers in greatest dimension) and lack of polar filaments. In contrast, H. nana eggs are 30-50 micrometers in greatest dimension and have polar filaments radiating out from the inner shell. Both eggs have an inner shell surrounding the 6-hooked onchosphere and an outer shell.
Here are some of the defining features of H. diminuta eggs: