The other day we went for a stroll along the river and saw a ghostly tree. It stood out like a sore thumb around the rich, green foliage: it was completely white with no leaves.

We walked closer trying to find out what it was: was it an art statement or maybe an act of vandalism? We were busy discussing various possibilities but as we got closer, we fell completely silent.

The tree was covered in a web of white silky strands. And it was alive.

It was alive in more than one sense of the word. It was alive with tiny caterpillars crawling all over it. The grass area surrounding the tree was yellow - that is, the part of the lawn which was infected by caterpillars. Tent caterpillars, to be precise.

The local birds were quite enamoured by this tree and happily swooped down for an extra juicy caterpillar or two whilst completely ignoring the two foolish humans below. One bullfinch even posed for a photo or two whilst enjoying the caterpillar buffet.

And at home the internet provided us with answers and I realised that things could be a lot creepier than just a single ghost tree down by the river.