Some years ago, a colleague held an open house for our office at Christmas time. He took pride in showing us the special gift he and his wife had chosen for their twin daughters: a pair of long-haired guinea pigs. The purveyor of these appealing rodents had not been able to verify their gender – perhaps, because of the long hair?
Having no desire to breed the long-hairs, my co-worker had devised a method to keep them separate until they could know if they were same gender or a mixed pair. Their glass cage had a cover and he rigged a solid “wall” reaching from the lid to the floor.
When we returned to work after the weekend, I asked the doting father if the protection had worked. It seemed that, when the parents had come down to check in the morning, they found the pair on the same side of the impenetrable barrier – in a state of cozy propinquity. About six weeks later they had final confirmation that, indeed, the long hairs were of different genders.