In fact as others said co habbing is not a good idea and can be very very serious, in fact can mean the life or death of your little snakes esp. because your snakes are little and unestablished. Here are a few issues:
-your snakes are different sizes(possible cannibalism)
-your new snake has not be quarantined(separate rooms), nor has the other one(generally quarantine should be at least 3 mths), this allows for you to carefully watch the snakes and determine if they are healthy or not, without quarantine one sick/dead snake becomes multiple sick/dead snakes
-they are solitary, it stresses them to be together, stress weakens their immune systems, making them susceptible to illness/disease
-stress can cause non-feeding and regurging
-opposite sexes in the same viv can lead to premature pregnancies in females who are not physically ready, which leads to egg binding and possibly death
These are just a few of the reasons it is advised not to have more than one corn snake in a viv.
I suggest you immediatley get another set up for the new snake. Put it in another room, do not feed or handle that snake for at least 10 days so that it can build up stomach acids again.
As well I would suggest going to Kathy Love's website
http://www.corn-utopia.com/Corn%20Utopia%20on%20the%20Web/-%20TOOLS%20PRODUCTS%20herp%20Cornutopia%20corn%20snakes%20cornsnakes.htm and order NutriBac and put some on the pinkies of the next four feedings for both of your snakes. It is a probiotic and will help to balance the natural bacteria in the gut of your snakes. She suggests that with every new snake you acquire, you give them NutriBac as you do not know how stressful the last living conditions were or how unbalanced the gut load is. I use it with each of mine and esp. with anyone who regurges and it seems to do wonders for their digestion and appetite.
When you do feed next time only feed half of the pink and wait 7 days, if your snake keeps that one down. Then likely it was stress and your snake should be ok to move back to a whole pink on the next feed, be sure to cut the skin of the pink as it helps the stomach acid get into the pink and digest it quickly.
Finally as already mentioned, you need to check temps with a digital thermometer or an infrared temp gun, the stick on strips and dials are famous for being as much as 10-15 degres out either way. So really your temps could be as low as the 60's and as high as over 100!! This will also cause regurges. As well when you set up the new tank put the UTH under the tank not on the side, corns need belly heat to digest. Make sure you are checking the temp, right on top of the UTH as snakes burrow and will get to the heat.
Hope this helps.
