Black Snake

Question
A 4ft long black snake has moved in under our foundation. It has a big bulge about 3/4th way down, seems too low for it to be prey. I am wondering if it is pregnant or about to lay eggs, in which case, I probably should chase it away.  How can I tell?

Answer
Without handling the snake itself and even then if your not used to palpitating it can be hard to tell whether its food or eggs. Without knowing where you are its hard for me to say whether its food or not as most reptiles breed during the spring and "Black snake" doesn't really give me enough to go on to identify it.