I would suppose that they don’t “know” they just feel compelled. There are dragon flies that migrate from India to Africa. It takes three generations to comple

I would suppose that they don’t “know” they just feel compelled. There are dragon flies that migrate from India to Africa. It takes three generations to complete the round trip. So how do they know? It must be just a feeling. I guess that a long time ago when India and Aftrica were adjacent parts of Gondwana land, the migration must have been quite short. But as the continents drifted apart the dragoon flies had to adapt to the longer route.