That is seriously not possible.
Here is the output from some search commands.
Searching netbots.
[ppslim@services netbots] $ grep -r "invited" ./*
./botnetop.tcl: putlog "botnetop: invited $frombot (using nick $fromnick) to $chan"
./botnetop.tcl: putlog "botnetop: invited $frombot to $chan"
./botnetop.tcl: putlog "botnetop: invited $frombot (using nick $fromnick) to $chan"
./botnetop.tcl: putlog "botnetop: invited $frombot to $chan"
Searching the default Tcl scripts.
This produces 0 results, so there is no point
Searching the eggdrop source code.
[ppslim@services eggdrop1.6.12]$ grep -r "invited" ./*
Binary file ./channels.so matches
Binary file ./irc.so matches
./src/mod/channels.mod/help/chaninfo.help: invited to the channel (i.e. channel has mode +i)
./src/mod/channels.mod/help/channels.help: invited. The "(perm)" means that the invite is "permanent": that
./src/mod/channels.mod/channels.c: dprintf(idx, " To get invited I do: %s\n", chan->need_invite);
./src/mod/channels.mod/channels.c: (Function) NULL, /* [25] used to be isinvited() <cybah> */
./src/mod/channels.mod/channels.h:/* *HOLE* channels_funcs[25] used to be isinvited() by arthur2 <cybah> */
./src/mod/channels.mod/channels.h:#define isinvited(chan, user) ismasked((chan)->channel.invite, user)
./src/mod/irc.mod/chan.c: if (i->lastactive < now - 60 && !isinvited(chan, i->mask)) {
./src/mod/irc.mod/chan.c:/* Make sure that all who are invited on the userlist are actually in fact
./src/mod/irc.mod/chan.c: * invited on the channel.
./src/mod/irc.mod/chan.c: if (!isinvited(chan, ir->mask) && ((!channel_dynamicinvites(chan) &&
./src/mod/irc.mod/chan.c: putlog(LOG_MISC, "*", "%s!%s invited me to %s", nick, from, msg);
Binary file ./src/mod/channels.o matches
Binary file ./src/mod/irc.o matches
The was a issue sin 1.6.10, that caused a certain message to be sent to the server, though it waqs destined for the log file. This has been fixed in 1.6.12.
This isn't the issue here though. As the above output shows, the message you talk about isn't in netbots, the scripts included with eggdrop or the source code itself.
This sugests that the servers your bots are on, generate these messages.