Copepods are highly sensitive to temperature, and the species of pods we sell are also strongly benthic, meaning the prefer to go to the bottom of containers (or of your aquarium) in search of food. In many cases, this can make it look like everything is dead. Here's how you can be sure: 1. Float the bottle in your tank or sump for about an hour to temp acclimate it. Copepods that arrive cold will be very sluggish, in a hibernation-like state. As they warm up, they will become more active. 2. Take the bottle out of your tank or sump and invert it to get the pods up off the bottom of the bottle. Give the bottle a minute to settle, then shine a light up through the bottom of the bottle. You should see tons of movement. If after doing this you don't see much movement from the pods, please contact us so that we can reship your order free of charge. While rare, in about 1-2% of orders shipping problems do occur. We always make this right!