How heavy is the snake? How heavy are the mice? i typically feed about 10% of the snakes weight sometimes that means two small items rather than one big one. I have found the snake will let you know, after the meal if they return to the hide they are done but if they stay out and in strike mode often will take the second one. Sometimes they will no be very interested in the second but a day or two later they are out hunting again so I'll offer the other at that time. I really don't want to feed more than 10% or so. So usually offering two usually means they are 5% or less of the snakes weight. They generally will let you know when they are hungry.