Entity count keeps increasing

I am running a mini-game server and for some reason my entity count is going up significantly. As I am the only one who builds arenas on the server, how is it that we are gaining entities at such a rapid rate? Also running craggyisland so there is a very limited amount of trees, nodes etc

 

Have you got some plugin in place that stops players from building

 

There is no need for it, they spawn inside an initial lobby where they have no access to resources. And no way to escape any arena that they would join. Even if no one is on the server, the entity count is somehow increasing by quite a bit

 

What do you mean with increasing? Some hundreds?

 

like i don't log into my server for 2 days and my entity count has gone up 25k and no one has built anything...