Snakes, chicks and big dogs

When we put the last batch of chicks out I counted 22 birds after SAM put them in the out side brooder. I have counted several times and never got higher than 22 chicks.  If this is correct we lost 4 birds while they were in the bath room for a week and the only 2 I know about.   are the 2 that died the first morning when they got wet. Now we had 26 birds to start. I know because I counted them as they went into the plastic tub. If we lost 2 more it would mean a snake got into the tub in our bath room.
If there is a snake in that bath room and I go in there and see it I am going to die. I can not think of any other way we lost 2 extra chicks!
We have had chicks disappear from the bath room more than once since Sammy started taking care of the chicks in the last year. I always thought that they died and Sammy didn't want me to know but now I am beginning to wonder if we are having a visiting black snake in the bath room.
Clayton never told mama but while she was still alive he saw a six foot black snake in her bath room and it disappeared while he was hunting for a hoe to kill it.. He told me and I was never comfortable in that bath room after that unless the weather was really cold. He said he stopped all the holes up in there but I was still scared to go in there.
My shoulders were hurting all night.

We have stray dogs here all the time but we had a Great Pyrenees dog show up yesterday.  

The neighbor took it to his house because SAM said it was trying to get in the chicken pen and he was going to kill it.