In addition to the study above, the Federal Trade Commission (in 2001) warned manufacturers of these devices that they needed to support their claims with evidence in order to continue to sell the devices. They had specific claims that they found to be problematic, and also indicated that the idea of ultrasonic devices was problematic:
These are the claims that the FTC wanted the manufacturers to substantiate:
Eliminates rodent infestations;
Serves as an effective alternative to conventional pest-control products;
Increases or assists the effectiveness of other pest-control methods;
Eliminates fleas on dogs or cats; and
Scientific tests prove product effectiveness.
Prior FTC complaints alleged that any reaction by rodents to ultrasound would be temporary at best because rodents become accustomed to ultrasound and will return to their nesting or feeding areas even in the presence of an ultrasonic device. Furthermore, previous FTC complaints alleged that ultrasound devices do not control insects.
In 2002, Lentek International was charged by the FTC with making false and unsubstantiated claims about their pest-control products. In 2003, Global Instruments settled with the FTC. The settlement prohibited them making their claims about the devices unless they came up with substantiating evidence.