Where did supercolony Ravensheide-1 go?

Earlier this week I published some ant-road maps on Ant-maps.com. One of these maps shows the nest and ant-path structure from the supre colonie 'Ravensheide 1'. The structure counted at least 18 nest, including some nest one meter high. Some protected by metal cages to protect the nest against hungry woodpeckers.

Last year some of the nest were disapeared or a lot smaller than before. And today, when I visited the colonie all the nest were gone. Not one was active. Two new nest had been formed in the last 16 months, but even these 'new' nest were nothing more than a ruin. Only on one spot, now marked with the project-number Ravensheide-323, counted some ants... but no nest. That means some ants found a save place under the ground. Where did all the other ants go?

Here you fond a full list of Ravensheide.