If you consider that a queen’s brood production remains relatively stable over time, and youngest workers take on brood rearing tasks, the amount of ants in the nest remains somewhat constant over time. What really ramps up is the number of older workers that have gone through the mental switch to foraging outside the nest. Their pheromone scents change along with their whole mentality to be: explore, explore, explore. This is especially true with a large, solo foraging species like yours. All commercial formicariums fail miserably to take this into mind, as their outworlds are pathetically small. A much larger outworld would alleviate a lot of your difficulties now, but at the same time, keeping a pristine level of cleanliness may be a thing of the past.
My Crematogaster colony is probably about 8k or more now. I only clean once a year, during diapause. I can easily feed them without escapes, though, thanks to the two huge outworlds I made. The long tubing connecting them helps give them a sense of distance travelled as well.
This is totally spot on! A 3x2", even 3x4" little box is not enough for real foraging. My suggestion if you don't mind some very trivial DIY, make a larger outworld, here's a simple part lists, initial investment maybe around $50, but can make a couple for less after.
- https://www.containe...ductId=10023923 - High-Heeled Shoe Box Clear SKU #10048432
- https://www.amazon.c...s/dp/B08R852GJQ- Once you find a cable gland size for the tubing you like, you can get that size specifically to save cost
- https://www.amazon.c...g/dp/B06XWR2QD8- Try to get Ultracal30 due to low expansion, can get it from anywhere, and 5lbs goes a really long way
- Reptile sand - Wherever you find it cheap
Other items... stepped drill bits and some screening. I basically add some screen to the high heeled shoe box on the side vent holes to prevent escapees with a bit of super glue, and then cut a hole in the top and put some additional mesh to give some added air flow. Drill at least 2 holes for the cable glands for passing through the vinyl tubing. Add the ultracal30 maybe 1/4" thick, and then sprinkle sand on top. Once it's set, takes a day or too, add a bit more sand and maybe some aquarium pebbles or whatever decor you want.
It's maybe an hour worth of work, very basic DIY, and you'll have a large expandable setup for your outworlds. As the colony grows, can add additional ones for them to go to. TBH you can go different routes... 3D printed connectors, or rubber gaskets, etc, several ways to go. It will be SO much easier to maintain with a larger outworld and much less concern for escapees.
Looks like I need to clean the top again of dust and sugar pieces, lol so excuse the mess. Their trash pile is cleaned up yearly, so that's the last 6mos or so of trash from these. Test tubes are need to be replaced shortly as well obviously as getting low, this is one of my P. occidentalis setups. You can also go neater on the super glue for the screening, but I went for functionality over beauty on this one as they needed it.:
Edited by noebl1, June 30 2021 - 4:11 AM.
I always have 70+ workers in the outworld with 100+ in the nest. Too many to count. I painted the inner surface of the lid and a 1” rim at the top of the outworld with Fluon+. Even with ample time to dry, enough ants can still cross the barrier that even swiping my feather like a one-armed bandit doesn’t keep them contained. It’s almost impossible to clean the outworld or refill their feeding dish (trying to minimize fruit & insect parts being strewn around) without casualties or fatalities (good thing this queen is so prolific). I may have to go back to a quick chill just prior to feeding though I really don’t want to harm a colony I've had for 3 years. I’d be really interested in hearing how those of you with big colonies and active foragers in the outworld handle this!
Though I did put my “Gremlins after Midnight” C. penns in the cooler for 20 minutes, there were no formicine casualties or fatalities 
THIS IS MY MOST LOVED AND MOST PROLIFIC COLONY!!! I got out my aspirator and began sucking as if my life depended on it! Hell, I didn’t want to admit to my wife that my ants were loose on our 3rd floor after she’s allowed me to keep ants in the house, cockroaches, fruit flies, and crickets, in the freezer for the past 3 years (I did eventually spill the beans though). I either sucked up (too many to count) or killed (4-5) what I couldn’t catch and released the P. imparis queen. As I write this, I've been sitting in front of the Ant Closet for 90 minutes, aspirator at the ready (I just sucked up another two in the last 10 minutes). This could be a long night! I am sooo screwed 
At least the Fluon+ is still working!
