They are the devil to get rid of in the garden let alone indoors! Poor you ..I would suggest filling the gaps in your floorboards or if you can discover exactly where they are coming in put down some copper tape which they won't cross .Or try Slug Barrier from Bio which is crushed seashells.It may involve sitting up in the dead of night with a torch to find exactly where they come in though. Perhaps they are getting in through an airbrick or something.If you have any juicy plants in your room that will be what they are after. I wish you luck in getting rid of the blasted things.