too many connections

So I have a full page of server errors with "Too many connections". We are a small forum and particularly at that time of (my) night, it's real quiet, not much traffic so not getting this. Unless it's caused by spambots? Do I need to worry about this or can I just delete the errors and forget...

We have been getting the dreaded "Too Many Connections" error, and while I know that we can increase the number of connections, this is not the problem. The problem according to our host is that there is a query somewhere that is hanging, or potentially running and then leaving the connection...