The manufacturer has done extensive new research to ensure the Trelona Termite Bait Cartridges (TBC) are very attractive to termites. The intention is to move to annual checking of the stations to reduce the amount of times pro companies need to visit homes. The Trelona Termite Bait Cartridges (TBC) do need to be changed yearly so the expense is quite a bit higher than using the Termite Monitoring Base (TMB) and Termite Inspection Cartridge (TIC) which do need to be checked quarterly.