During serologic rabies surveys, bleeding is often difficult or almost impossible in small or endangered mammals such as bats. Therefore, the usefulness of an alternative, less invasive technique—that is, the use of blood-sucking reduviid bugs (Dipetalogaster maximus and Rhodnius prolixus)—was investigated. Bugs were used in combination with a conventional method (retro-orbitale bleeding) to obtain blood samples from the same individual NMRI-mice (Mus musculus) vaccinated against rabies. Rabies virus-neutralizing antibody (VNA) titers between paired blood samples obtained from the same mice were compared. The accuracy (between-method comparison), precision (repeatability of results), and robustness (influence of digestion on blood parameter) of the bug method was evaluated. VNA titers in the blood sample obtained from the bugs' crops were equivalent to those from samples collected directly from the mice. No differences between samples taken from different bugs that had fed on the same mouse were noted. In addition, there were no changes in VNA titers in blood samples collected from the triatomine bugs for up to 4 hr after completion of the blood meal. This study demonstrates that the application of blood-sucking bugs offers a validated alternative for obtaining blood samples to determine rabies virus–neutralizing antibody titers and is highly suitable for animals with limited or no accessibility of veins by conventional sampling techniques.