Can you house two garter snakes together?

Today i caught two garter snakes in two differetn areas, i have a 20 gallon tank and im planning to get a bigger one, the garter snakes are almost exactly the same size, they have been in the same cage for like 3 hours now and are both coiled up in the same hut, iim wondering is this stressful on them, im not shure how to sex them but if you do please help me