Have a bit played around, change the setting to about 5 in the Scala brought the success, but this frequency is also very disgusting,
she goes through my teeth on edge.
Conclusion: Just try and not give up right away!
Addendum: tonight it snowed and I could not see any cats traces in the snow in the morning, even outside
my property.
Apparently it has spread in the chicks - there were at least 6 to 8 - that what is unpleasant on the ears.
Hopefully it stays that way!