first off ill start by saying i dont know which snakes are male and which are female,,,the store did not know when i bought them either,,,i have a new eastern garter snake and hes little and said for sure to be a male,,,,the other two i dont know,,bought at same time from same place and there not eastern garters,,cant remember what they are,,,anyways one is 3 ft long and the other is about 3 1/2 ft long,,the smaller one has a narrow looking head and the bigger one looks like a muscluar looking head,,,now the biggest snake used to be really calm and u could hold it and play with it no problems,,,but in the last 3 weeks (she) has been acting jumpy at everything and she eats everything u put in front of her,,,shes really grown in the last 3 weeks,,,shes looking around alot in her tank (175 gallon) and when i drop food in she will bully the others and sometimes even take it from the other snakes,,lol,,anyone think this might be a female and maybe shes pregnant? heres a few pics of the two big garters

this is the new eastern

this is the two snakes laying on each other as they do alot

and here in another location in the tank


heres ones tail end

and heres the others