Installed since May, the ferries are placed in four locations: Ballycastle Seafront; Coleraine town center; Portrush Harbor and Ballymoney High Street.
Each voting box displays one question and two answers. Smokers will vote by putting their cigarette butt in the slot under the chosen answer. Cigarette butts pile up behind the clear glass front in two columns indicating which answer is the most popular.
Trash can maker Hubbub says the smart incentive has been shown to reduce cigarette butt waste by up to 46%.
Causeway Coast and Glens Borough Council Mayor Cllr Richard Holmes said: “Participating in this trial allows City Council to collect cigarette butts that are too common on our streets while raising awareness of an often overlooked type of litter.
“Despite their small size, we know that cigarette butts are harmful, especially when they end up in rivers or the sea. We need to be more aware of the negative impact of throwing cigarette butts on the ground or in the sewers. .
“A cigarette butt can pollute up to 7.5 liters of water, leaching chemicals that are harmful to wildlife. Collectively, the negative effects of this could be enormous.
“While there is a fun element about this type of bin, there is also a serious message behind it. “