First it was wild boars, now it's all about the worms. Hertha Berlin, who keep complaining about the state of the pitch at their Olympic stadium, have finally identified the culprits.

Small worms have proliferated under the heated pitch this winter and are devouring the grass, the daily newspaper Bild said on Thursday. "We're not looking for any excuses for the way we play but the pitch really is a catastrophe," said coach Juergen Roeber.

The pitch will now be covered with acid sand to fight the worms but this is not the first time that Hertha have had problems with animals. Last year they complained about wild boars digging holes in their training ground. That problem was solved with the shotgun.