  We revisit the numerical evolution of Ellis-Bronnikov-Morris-Thorne
wormholes, which are constructed with a massless real ghost scalar field. For
our simulations, we have developed a new code based on the standard 3+1
foliation of spacetime. We confirm that, for the massless symmetric wormhole, a
pulse of regular scalar field causes the wormhole throat to collapse and form
an apparent horizon, while a pulse of ghost scalar field can cause the wormhole
throat to expand. As a new result, we show that it is possible for a pulse of
regular matter to travel through the wormhole and then to send a light signal
back before the wormhole collapses. We also evolve pulses of matter traveling
through massive asymmetric wormholes, which has not previously been simulated.
