Is this horrible to find in the garden? I've never seen these before.

Is this horrible to find in the garden? I've never seen these before.

Observation - Is this horrible to find in the garden? I've never seen these before. - UK and Ireland. Description: I found these when I went to clean out our hedgehog house today. No hedgehogs in the last year unfortunately but I found that the pond-liner covering was attached to the wooden top of the house by the silk surrounding these grub/caterpillar things. The g

I found these when I went to clean out our hedgehog house today. No hedgehogs in the last year unfortunately but I found that the pond-liner covering was attached to the wooden top of the house by the silk surrounding these grub/caterpillar things. The grubs appear to have eaten channels of the wooden top of the house. I've never seen anything like this before and just want to know if I need to worry about them. The hedgehog house is buried in a woody/shrubby area of the garden and is only disturbed once a year for cleaning. nothing like this found before (although this is the first year we haven't had a hedgehog in the house too).