Okay, before you panic, a lot of people get spooked about this after they buy a new culture.

Are you worried because you haven’t seen them in a long time, or do you see them and they are all dead? If you see them and they’re dead, well jeez buddy. I’m sorry! Otherwise, take a breath and relax. The isopods are okay. Continue to tend to their enclosure as if they are alive. 

Whenever I release a new culture of isopods into their enclosure, I say bye (yeah I talk to them sometimes, what about it?!) and hope I see them again in the next few months. I’m not exaggerating. I have had new cultures disappear for months without sightings, then one day I discover a giant brood of babies!

This is not a hobby for impatient people. Isopods like to hide! If you designed your enclosure well there will be plenty of hidey-spots and leaf litter for cover. They will burrow into their substrate. Some varieties are tiny. Plus a lot of types have mighty good camouflage.

There is no need to go digging around in the dirt looking for proof of life! That's more likely to just stress them out and delay reproduction. If you want assurance they are okay, try looking for other signs of isopods.

Frass

Isopod droppings, called frass, are a distinctively rectangular shaped and flat. Check surfaces like leaves and the top of their cork hide for new accumulations of frass. If you aren't sure how old the frass is, clean it out and see if new droppings appear.

 

Leaf skeletonization

Leaf skeletonization is a sure sign your isopods have been at work behind your back. I set up my isopods with a mix of thick and thin leaves because isopods can find it difficult to eat hard leaves like oak and magnolia. Alternatively, you can pre-soak harder leaves. Point being, give them a soft leaf on day 1 and you will see clear evidence they are alive as the skeletonization advances. Hong Kong Orchid leaves are a favorite soft leaf with my isopods!

Burrow holes

Isopods are avid burrowers and given enough time they will make holes in cork hides and even limestone. More commonly you'll see burrow holes in their substrate. My White Sharks made a bunch of holes in the soil under their cork:

 

See? Right there! Okay it can be pretty hard to see, it looks like someone aerated the soil with a toothpick. Sometimes you have to look at the right angle for them to be visible like a dirt Magic Eye, and all of a sudden you'll see clusters of small evenly-spaced holes.

A word of warning

It can be tempting to offer a variety of treats to lure your isopods out of hiding—and it can work—but be cautious not to overfeed. Overfeeding will invite soil gnat and soil mite populations to bloom before your culture can get established. I usually don't offer new colonies treats for the first month (when starting with 10 counts), because in my experience they will ignore the food or only pick at it until they are more established. In the meantime they have plenty of leaf litter and substrate, which is all they really need at the end of the day!

If you do use treats to attract them, try something like a baby carrot that is less likely to mold. Remove uneaten food after a couple days, and check whether there are bite marks or pieces of frass on it.

When do I give up?

If it has been several months and you aren't seeing any build up of frass on surfaces, leaf litter isn't disappearing, food is left untouched, and dirt is undisturbed, there's a good chance they are in fact all dead. Don't be too fast to give up hope though: if you started with a small number of isopods in a large enclosure—like a 10-count in a 10 gallon tank—they can "disappear" for long periods without much outward sign before the population suddenly blooms.

Even if you fear they're all dead, sift through the enclosure contents to catch any lone survivors before tossing the culture.

Okay but how can I see them more often?

Think about ways you can design the enclosure to encourage your isopods to put themselves on display.

• Sticks are fantastic. For whatever reason, many types of isopods are compelled to climb and explore vertically. Give them things to explore! If you get your hands on sticks with lichen that's an added bonus since isopods love to eat it. Just watch out for escapees: sticks and plants shouldn't reach the top of your terrarium or isopods will start to find their way out. Where I live, that means desiccating pretty quickly :(
• Cholla “condos.” I use cholla branches in a lot of my enclosures. With branches with smaller holes, adult isopods can be too large to climb through while babies weave in and out as they please. Adults stake out the open ends of small branches as prime territory.
• "The viewing dome" The viewing dome was my invention™. Okay, it's just an eggshell. But if you eat eggs, save a few shells for a super easy multipurpose isopod treat and hide. Isopods love to eat the membrane off the eggshell, so put it up against the side of the enclosure. The white backing provides contrast to easily spot your isopods munching away. I had no idea how many White Sharks I had until I gave them an eggshell! Once they are done with the membrane, flip the shell over to give them a hide that is also a source of calcium.