Sentence:  Bats host many high-profile viruses that can infect humans, including severe acute respiratory syndrome and Ebola. A recent study explored the ecological variables that may contribute to bats' propensity to harbor such zoonotic diseases by <WSD>comparing</WSD> them with another order of common reservoir hosts: rodents. 
Meaning of the word marked with <WSD> tags:  To assess the similarities and differences between two or more things ["to compare X with Y"]. Having made the comparison of X '''with''' Y, one might have found it similar '''to''' Y or different '''from''' Y.