Is there any evidence that sonic devices are effective at repelling and deterring rodents, particularly roof rats? If so, what devices are most effective?

Thank you,

Bob

I am sure you have seen my posts about my rat problems... I have installed 4 sonic devices, and sadly enough they seem to be doing NOTHING! I am using RATZAPPERS and eliminating them one by one.

I've used them for mice and they worked very well, but rats I have no idea.

I forgot to mention that there are several varieties of sonic devices, the high end ones have a sonic/sound control, and they may work better for rats. Turned up to highest level, some of my friends were able to hear them, & my son (when he is home on weekends) thinks they are what's giving him headaches.