  It was recently argued that the pigeonhole principle, which states that if
three pigeons are put into two pigeonholes then at least one pigeonhole must
contain more than one pigeon, is violated in quantum systems [Y. Aharonov et
al., PNAS 113, 532 (2016)]. An experimental verification of this effect was
recently reported [M.-C. Chen et al., PNAS 116, 1549 (2019)]. In another recent
experimental work, it was argued that two entities were observed to exchange
properties without meeting each other [Z.-H. Liu et al., Nat. Commun. 11, 3006
(2020)]. Here we describe all these proposals and experiments as simple quantum
interference effects, where no such dramatic conclusions appear. Besides
demystifying some of the conclusions of the cited works, we also present
physical insights for some interesting behaviors present in these treatments.
For instance, we associate the anomalous particles behaviors in the quantum
pigeonhole effect to a quantum interference of force.
