@PjsherEEN A couple things. That article doesn’t have references. Also I confirmed it is only in the anime. Episode 207
“The anime has depicted kikaichū with several qualities that aren't seen elsewhere in the series, or at least aren't said outright. In one episode, kikaichū are shown to be effective counters against genjutsu , because their nervous systems aren't complicated enough to be affected.”
This is from the kikaichu wiki