Thank you to everybody who took the inspection quiz.

On this occasion, collective wisdom did not fully provide the correct answer: 12 out of 23 responses correctly identified the cause of the damage as eating or chewing animals. Specifically Squirrels (view the collection of results online)! Both species gnaw on aluminium to file down their continuously growing incisors (teeth); however, in Europe, Grey Squirrels are mainly found in the United Kingdom, Ireland and Italy. Grey squirrels are native to North America and Canada. There are an estimated 2.7 million grey squirrels in the UK (first reported in 1876) and these present a threat to the indigenous 287,000 red squirrels as well as to aluminium ferrules!

Should you know this problem from other regions or other squirrel species too, please let us know.