I went on a wildflower walk with Derbyshire Wildlife Trust this evening and we went inside a cave too. I spotted this cave spider egg sac hanging on the wall and then saw a couple of cave spiders above!
@flowerfairyann@pennystot They're not that big... there is a (blurry) photo of one on the blog via the link above but there isn't anything for scale. They're similar in size to house spiders... here's a photo to give you an idea if you want to look! http://www.ispotnature.org/node/279249
http://www.ispotnature.org/node/279249