A Nairobi court has adjourned to April 23 the sentencing of four men who pleaded guilty to attempting to smuggle hundreds of highly sought-after ants out of Kenya in what conservation officials are calling a "landmark case" of biopiracy. The accused - two Belgians, a Vietnamese national, and a Kenyan - admitted to attempting to illegally export the giant African harvester ant (Messor cephalotes), a rare species prized by exotic pet collectors. Some dealers in the UK value a single ant at up to £170 ($220), making the consignment potentially worth tens of thousands of dollars.