Evidently so, and they do odd things.

The erratic behavior of Pluto’s moons is the fault of the dynamically shifting gravitational field created by Pluto and Charon. For many years it was thought that Charon was Pluto’s lone moon, but in the past decade astronomers have discovered four minor moons orbiting what is really a binary planet system, made up of Pluto and Charon mutually orbiting a center of gravity between the [sic] them.

In other words, Pluto and Charon are like twin bodies engaged in an eternal and rambunctious dance, while four smaller moons orbit the pair. But the gravitational field created by this dance is much more complex than the one generated by the simple rotation of Earth. This fact, combined with the oblong shape of the smaller moons, is what the researchers believe causes their odd movements.

Science is wonderful.