I've read up on it, some say it's a variation of sleepwalking. Some suggest that it could be tiredness, stress, eating junk before bed - you know, the usual. I tested it out, and I eat hours before my bedtime now and we don't really eat junk food now and it still happens. My only theory is tiredness I suppose. Although I watched 'The Fourth Kind'... remember the owl? 'It's not an owl...' Freaky, but my god I proper spooked myself out last time I had these hallucinations and Grant wasn't home!
A couple of times I saw something that wasn't really a spider it resembled more of a moving, black scribble and when I first got the hallucinations 10 years ago the spider-like object had shorter legs and was glowing slightly.
So I am staying up as late as possible to see what happens. What will probably happen will be me passing out in an hour or so and waking up at 06:00 tomorrow cursing myself for being such a mind-numbing idiot for not going to bed at 21:30. Tomorrow, 21:30 - I promise!
Meanwhile, the spider mystery remains unsolved...