beetle identification Belgium: xylophagous?

[Pezpollo]

Hi all,

Could somebody please help in identifying the following specimens.

Geographical zone: northern Europe, Belgium.

They are approx. 16 mm long.

My parents found these specimens in their attic. The burning question is whether they are xylophagous (Anobium punctatum...?)

Many thanks.

[alandmor]

It appears to be an adult Tenebrio molitor, the common mealworm, family Tenebrionidae. Commonly used and sold as food in pet shops.

https://en.wikipedia.org/wiki/Mealworm

[Pezpollo]

Thank you.
What source of nutrition could they possibly be living off I wonder. My parents would have left no type of food of any kind in the attic (my father is a neat freak).