Eves thinks his explanation may also help to explain other phenomena during eclipses. Infrasound may be responsible for strange Foucault pendulum behaviour (the sensitive pendulums – used to demonstrate the rotation of the Earth – swing wildly during eclipses). The infrasound pulses may cause the ground to vibrate, interfering with the pendulum swing. Infrasound may also explain some bizarre animal behaviour during these events. Sub audible sound wave frequencies are known to distress or alarm birds, perhaps their strange behaviour during eclipses could be down to infrasound propagation.