When we remove that fear from a particular cage, disconnecting it from the collective body of fear, removing the vibration of fear from the fish, (and the personnel working there) the fish stop attracting lice, because lice are attracted by the fear vibration.
This is just one of the strategies we use with the Bioemitter Farming System to deter and control the populations of sealice in salmon farms.
Phil Callahan was one of the relatively unsung heros of the development of understanding of the transmission of various frequencies by living organisms to attract a mate, for example, and how injured or stressed creatures give off the signals to attract predators.
Its the same with humans and mosquitoes – some people get bitten and some don’t. It’s the vibrations we transmit that attract them. Stop the vibrations (in whatever way) and you won’t get bitten.