Similar looking grubs are the rose chafer and the stag and lesser stag beetles which you'll find in rotting wood and also in compost heaps, and they should be left alone - I believe they are in decline in some areas.
Here's a brilliant site with photos and gives more info.
http://maria.fremlin.de/stagbeetles/lar ... index.html
I must admit I gave several icky bugs from the compost heap to the chooks until I found out they were good bugs!
