Well I went to feed my ADFs and I saw one ling on he edge of my filter. I have a Tetra In-tank filter and it doesn't ave a top cover. It looked like it was about to go in. Then I noticed my other ADF was missing. I thought he was just hiding like normal but after about 15 mins of searching I decided to look in the filter. I lifted one of the filter cartiges up and out shot the ADF. So is there a reason they would be going in the filter??