Rats can hear ultrasound: the range of the rat''s hearing is around 200 Hz to 80 or 90 kHz (Fay 1988, Kelly and Masterson 1977, Warfield 1973). There is a whole world of high frequency sound out there that rats can hear that we cannot, a perceptual difference that humans tend to forget (Milligan et al. 1993, Sales et al. 1998).
We hope that most problems will disappear within a few days. However, if the rodents have already built a nest in your house, they are unlikely to desert their young until they are old enough to move
Fortunately, rodents mature quickly and the babies will be fully grown within a month. If you suspect that there is a nest in your house it may be worth using traps as well, but remember that traps alone do not provide a long-term solution to your problem.