>They are going in circle?
>
>>Three worms going in a line.
>>
>>First worm says: there are two worms behind me.
>>
>>Second worm says: there is one worm ahead of me, and one worm behind me.
>>
>>Third worm says: there is one worm ahead of me, and one worm behind me.
>>
>>How is this possible?

No, in a circle all three would have one ahead and one behind.