Corn snake Black Around his Tail

Question
I noticed that my cornsnake has a black spot around the very tip of his tail. I don't know what it is and what to do.  Can you Please Help us Kevin.  It is our first cornsnakes.  We have had it for about 6 weeks and it is less that a yr old baby cornsnake.  Crawley is eating well and shed very good about 4 wks ago and shed all in one piece.  Thank you Kevin.

Answer
Hi Zoya,
  Do two things. First off check your husbandry to make sure that it is all good. Google corn snake care sheet and you will find all that you need. Secondly, take a picture or better yet several of them and email them to me at lasher9@gmail.com. I am not a vet, but i am glad to take a look and let you know if I think he needs to see a vet or not.