I have read more than once about snakes lack of intelligence. I do not believe this to be true. They usually site the cases that a snake uninterested in food became the dinner of the prey item. Pointing out that a captive snake will just lay there and not do anything while a live rat or mouse chews away on it. I do not believe this would happen in the wild to a healthy snake. Captivity is bound to change any animals behavior.
I have seen intelligent behavior in more than one captive snake. Alice has surprised me in that she has picked up on the feeding routine so well that I might have to change the routine to keep it fresh. I have a storage bin that I put her in to feed her. It has a hide box at one end. I will put her in the bin and guide her towards the hide box where she will curl up inside and wait. I then get the pre-killed mouse ready and remove the top of the bin. Using tongs, I will drag the mouse around to stir up the prey drive. Once she grabs it, I close the lid and leave her alone for an hour or two. After eating, she will go back inside the hide box. To transfer her back to her cage, I cover the entrance to the hide box and pick it up and place it back in her enclosure. This makes the transfer back easy on her after she has eaten.
With each feeding, she seemed to be more in tune with the process. She started to keep more of her body outside the hide box waiting for her dinner and coming towards it as soon as I placed the food item in the bin. On the eighth feeding, she crawled to the side of the bin I open to put the mouse in as soon as I started to remove the top. I barely had the mouse in the opening before she snatched it out of the tongs. This I believe is a learned behavior. They may have a small brain cavity, however they are quite capable of storing and using more than just basic survival skills.