I have a 10 gallon tank with one male betta and one otocinclus. The betts has been in there 6 months and about a month ago I got the oto. The betta has not bothered the oto. It seems like he does more defensive behavior like resting on the plants in order to blend in. I would think that is a normal reaction and isn't a sign of being overly stressed by the oto. I am thinking of getting another oto or 2 or 3 to keep the one company. Is there any concern about freaking out the betta by doing that?