I didn't see any on this visit, but there are so many places to hide that I didn't spend too long looking. It's a brilliant and very clever little enclosure.
Actually I think it is. This is the first time I can remember having difficulty finding a harvest mouse in its enclosure, and if I had more time to spend at the centre I'd probably have spent longer here.
The enclosure is quite new, so maybe they're still settling in, or maybe a few more mice would improve visitors' odds - but I can imagine more than 30 mice disappearing into those reeds without any hint of their presence. I think it's a great alternative to an ornamental pond though, having to look for several tiny, highly active animals.