ball python throwing up

Question
i have a 2 year. old ball python. i fed him yesterday and when he ate it he didn't wrap himself around it but he kind of regurgitated spit  while opening his mouth really wide then he just took and ate it without trying to constrict it. it wasn't a live mouse. and today it threw up part of the mouse. what should i do and why is this happening?

Answer
It sounds like he's ill.  I would schedule an appointment with an experienced reptile vet, right away.  Snakes rarely regurgitate unless disturbed right after eating (they lighten themselves so they can flee faster).  Regurgitation is traumatic and serious, because their stomach acids are extremely powerful.  (Give a snake 2 to 3 weeks off without food, to recover from regurgitation).

Check your temperatures first.  Low temperatures can also cause regurgitation.  The air temperature in the enclosure should be 80F, with a 90F basking spot.  Exact temperatures are very important for ball pythons, they are sensitive.  Humidity should be 60%.  Measure temperatures using an indoor/outdoor style digital thermometer with a remote probe.  (The stick on dials are about as accurate as using a drawing on a piece of paper).

Your description of the snake expelling saliva or mucous suggests he might have a respiratory infection, which is another problem that can happen with incorrect temperatures.
Fortunately, with PROMPT attention, this is very treatable, and relatively inexpensive to treat, so definitely get him right to a vet.

Also, a 2 year old ball python should be eating more than one mouse per week.  Most snakes of this age are between 500 and 1000 grams, and can swallow hopper or small rats...or 3 or 4 mice.  You'll want to get a weight on him, as there is a chance he is underweight (and probably smaller than he should be), if you have been feeding single mice.