Digital harassment sounds irritate animals and bird pests so they leave - for good! Sounds are not species-specific so they are effective against all animal pests plus bats and rodents. Choose any or all of eight harassment sounds then set the volume mute time between sounds random play and hours of operation. Repeating cannons and pyrotechnics don t work - animal pests quickly get used to the same sound. But CritterBlaster PRO electronic animal repeller features eight harassment sounds that can be programmed in hundreds of different combinations so animals can t acclimate to a fixed pattern.