Hello, I have a large pond in my garden which has been running for about 5 years. I have 7 medium to large size goldfish in it. 2 Shubunkin, 3 Common and 2 Comet goldfish. I noticed this morning whilst feeding the fish and doing maintenance that 3 of them seem to have just vanished out of thin air with no clues whatsoever. I have ruled out the possibility of it being a predator as there is a net over the pond and 2 motion-activated security cameras facing it which would have been set off if a predator came by. Plus I live in the UK and in the area, I live I have never seen a heron before and the only wildlife I get is domestic cats and foxes which at the most will take a glance at the pond and then run of. I have also ruled out the possibility of them jumping out as the net completely covers the ponds surface and the area around the pond is completely clear after a thorough search. The fish missing are 2 common goldfish and 1 shubunkin and these fish are quite large so I am almost certain that there is not enough space for them to hide as the rocks in the pond do not have enough space under them for 3 big fish to hide under. I am very confused as the 4 remaining goldfish are showing no strange behaviours and schooling together normally so if they would have been spooked by something they would have been hiding away as well. At the moment the only idea I have is that if I see no sign of them in a few days I may drain the pond and take all the rocks out and see if I can find anything but other than that I have no idea where to go from here. Any advice or suggestions are greatly appreciated.