Migrated to Synology - Whats the story behind all those @eaDir files?

[bbrip]

Slightly off-topic maybe, but I migrated from my old ReadyNAS NVX to a beautiful new Synology NAS box. All is well so far and got MinimServer running, but I got tons of "@eaDir" directories which must have been created when copying stuff across from the ReadyNAS (??).

Now, what do these directories mean, how do I get rid of them and how do I avoid that they get created again?

Many Thanks
bbrip