When my snake gets like that I know it's hungry. It'll get right up to the edge and just sit there looking at me with this attitude like 'I know you see me waiting here'. I think it's not impossible that your snakes are sensing the hormones/pheromones but I have no idea what effect mammalian hormones could have on both male and female reptilians that would cause them to react identically.

Hunger is definitely the trigger that gets my snake to behave the way you described.