Mantis?

[shag26272]

I have a 6 gallon nanocube and every now and then I have been hearing a click-click there is nothing I can see , what should I do?

 

[Hutton]

could be a mantis, pistol or a rattly power head

 

[shag26272]

I have no powerheads except for 1 minijet 606 that sits on suctions and is dead quiet. At first I thought maybe it was the tank and it might be but I am not sure. It is always 2 clicks in a row.

 

[Hutton]

usualy the clicks will go on if it is a mantis excavating rock... could be a pistol, wtach the tank at night to see what comes out. i have seen things i have never seen before when the lights were out.