Bugged by the persistent invasion by these birds of their paddy fields, where a special salt resistant variety of rice called 'pokkali' is being cultivated, an Ernakulam-based association of farmers has moved the Kerala High Court urging it to declare this particular species of swamphen as vermin. Pokkali cultivation is a form of mixed farming, where five months are devoted to growing rice, another five months for prawn or fish breeding and remaining 60 days are a transient period between the two, the petition has said.