You know how if you click on critters a lot, they explode, right? Well, I was wondering if there was any way to make them not do that. In the mean time, I'll just use a Civilian.

Is this for a single-player map? If so, if the player wants to waste his time clicking on a critter so that he can mess up the game he's playing, I say let him.
There is no way to stop the exploding critters as far as I know, but you can use triggers to detect when the critter is no longer in its location. If a player makes it explode, then the trigger will detect this and you can do whatever actions are necessary.

it only works under "single player"
...
and use b-net / UDP single player instead^^

You obviously cannot prevent them from exploding.

You can just give it to another player after a certain number of clicks(use EUDs) and then give it back, so it resets. But seriously, it only happens in one player, there's really no point, and if you can use a civilian instead, it's better.

I would say make it so you can only play it in some form of Multiplayer mode.
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