Do you know what it is???

A few days back I was walking back from class and I found this peculiar insect. It resembled a Snail but was different.....the difference being the back had something resembling logs of wood. And just as the snail goes into the shell when troubled, this particular insect did too. I came back to my room, pretty fascinated with what I had seen.
The same evening , a friend who noticed me observing the insect, clicked a picture and sent it across. I have been wondering what the insect is.

I have uploaded a photo of the same above ( Thanks to the friend who clicked it and sent it). If you happen to know what it is , do let me know!!

PS. Please do not think I like insects... I detest them.....this one was just out of curiosity .....Call it Fascination!