So I have a unique case in that I am converting lots of fruit to worms. I have a serious problem with water that I had to take care of and I am using cheap materials that I can get past my wife without raising alarm. Also I have found that the ramp concept is good but hard to construct in the inside of a tub. This is the design I have so far.




I believe the key to managing the exit of the BSFL is understanding that they are blind. The following rules can be applied.
1. BSFL will continue in one direction until they meet an obstacle (be that obstacle food or any other slight bump)
2. BSFL tend not to cross acute angles that are sharp. (rounded corners are another issue)
3. BSFL favor a right or left turn over raising their bodies up (they like to keep as much of their body in contact with a surface at all times).
4. Dark BSFL go towards dry. Light BSFL tend towards moist.
5. Any BSFL can climb almost any container when wet and presented with only obtuse angles to cross. (any angle presents the potential for the BSFL to "scan" around that is feel for a potential new direction to go in)
6. BSFL want cover and so tend to crawl into cracks
7. BLACK BSFL seem to prefer going against gravity as apposed to down.
8. All BSFL run from the light. Whites more than blacks.

BSFL that are ready to go to the next life fall out of the holding wash basket into the tub.

I put playdoe between the stick and the tub but made sure to scrape away any playdoe that was sticking out (bump issues and possible makes rounded angle). I am using playdoe because it is easy and available. I have not had trouble with BSFL digging into the playdoe only going in the joint between the playdoe and another object.

The single stick diverts the BSFL that are circling the inside of the tub above the moisture on the inside of the tub. The BSFL feel to the right and the left to see which way to go. Black ones tend to go up. (some do go over the stick, I may need to put future board on the stick). They come to the top of the tub and then they feel again they see the ledge and follow it sticking to the playdoe. When they reach the ledge they try to go to the underside but the tube edge does not allow them to fold their body around crawl under the ledge and they fall into my waiting cylinder.

I put cloth in the cylinder because I found the BSFL like to feel safe under something. It is the rainy season and if a BSFL is determined to get out he can. I had a few nights where I thought I was going to have a great take but then wake up to find that they had all gotten away. I then started to put flour in the cylinders but when the numbers are great that does not deter them either.

This design is not good when there are a lot of BSFL exiting at the same time because BSFL can act as obstacles to other BSFL thus changing their trajectory. (however this situation is less prevalent in this design over the ramp design because with then ramp there is a larger area that is close to the top of the tub and so their is more are for alternative paths up) I believe the cluster-f**k situation is a problem in most designs when there is a mass exodus. (this design seem to be a minimum, my cluster-f**k occurs when they are deciding to let gravity do its job or not-- they pause at the edge) Once a BSFL creates a path up the side of the tub because his friend redirected hit trajectory others ten to follow him up.

Tim

Here is another image for your enjoyment... You will notice a slight cluster-f**k. The ones that don't go down ten to follow the edge back into the tub... I'll get him next time.

Thanks for the photos Timothy. It's interesting that the BSFL are not digging into the playdoe only going in the joint between the playdoe and another object.

Will an overhang stop them from escaping?

I thought about a roof but I have seen them actually move on the underside of the rim of the tub. I think the biggest deterrent is sharp angles. When they can't lay a good portion of their body flat against the surface they tend to loose their balance. On the other hand in crossing the angle between vertical and horizontal that a roof offers they are likely to loose their footing. The cloth seems to keep them happy. I have thought about putting a line of soap around the rim under the theory that they are using the surface tension of water as their glue, but I haven't gotten around to doing that yet.

If there was a biology major or computer science major out there looking for a thesis I think you could model their behavior on a computer with a set of rules. There are a few rules that I don't know which one dominates over the other. I have seen regular maggots that behave very different than the BSFL. Some BSFL will actually go into reverse if you put a light on them where most maggots will ignore you. Most maggots are more likely to go off the rules displaying random behavior, but It also may be because they are smaller and a small obstacle looks like a larger one.

I recently read another post where someone experimented with an electrified boundary to contain the BSFL, similar to what some have done with worm bins. It was simply two strips of metal tape spaced ~1/8" apart, around the inside top edge of the container, connected to either pole of a 9V battery. If I can find the thread, I will add a link here. It seemed to work great. I believe the idea of that thread was to contain BSFL that had already self-harvested into a container. But I think that method could also be used in the main bin to avoid unwanted escape, and (in conjunction with physical breaks according to the behaviors you have noted) to restrict to a specific crawl-off path. Awesome job BTW, on characterizing those behaviors. You must have taken some serious time to observe the little guys!

That was me (link). It does need further testing in humid conditions as condensation might cause a partial 'short circuit' and quickly discharge the battery.

Tim this was a test I ran over a couple of hours where no larvae were able to navigate the 'overhang' to climb out of the inner tub. Without the overhang they had no problem. The tub walls were spritzed with rain water a couple of times during the test to simulate condensation.

BorealWormer, It looks good. If I had the materials on hand I would construct one for myself. Since you have the setup, maybe you could try making rounded corners (or two obtuse angles) inside between the walls and the lid and see if they make it to the underside of the lid. My guess is that they would be stopped by the inside edge with that setup but could make it to the point of clinging to the roof of the lid. Also I think the experiment would have to be conducted for 8hrs in the dark because the first few BFSL probably would fail but they seem to prepare the way by wetting the surface for those who follow. There also may be a difference between plastics as well. I have observed that one brand of water bottle seems to keep them in more than another brand. Hydrophobic plastic? I wonder if you could use that difference in an advertisement. "We have BSFL proof water bottles"

For the overhang it's just a margarine tub with a circle cut out of the lid. I'd be interested in how it performs in real world humid conditions.

I'll see what I can find. In Thailand here margarine is harder to get a hold of than butter, but it looks like an interesting experiment. I have shied away from a rim because I would have to extend the plank for the BSFL to walk. I couldn't put the cylinder close enough to the tub to make the BSFL fall in the hole. Also the most readily available container for me has been old water bottles; however, an independent experiment sounds OK. I saw the sun for more than two hours yesterday for the first time in a few weeks. The lack of sun has also hindered my azolla-BSFL waste experiment.

I can honestly say that a moist environment stimulates the black ones to migrate out. I added some water to the top of my stack and I was rewarded with lots of black grubs this morning. It have not been getting the numbers i am used to lately because my food I put in is dryer. But add a bit of water and here comes the grubs.

So I have been running this design for a while now and it has held up. I have washed out the tub a few times but nothing significant. There can be an accumulation of liquid which I have to dump out from time to time. If I don't feed the guys fruit for a while I have to wet it down to encourage them to leave the dry areas. It has been very sturdy and when I feed them a lot, I get good harvests. The cloth in the collector has been great. It seems to keep them in the collector quite nicely.

I am now trying to figure out a way to transfer my larvae from one of the full units to a new units. I have put a little basket in the big basket with fresh fruit and I am hoping that I can eventually get the larvae to go into that basket -- periodically dumping the little basket in the other unit. When I get the left over material I plan a couple of experiments. The first is using it as fertilizer for Azolla and the second is dumping it in my compost heap. I have noticed the liquid I get and dump in with my Azolla is rather strong and kills them... I need to water it down. Also I still have lots of frogs around that lay eggs in my ponds and have their little ones eat up my Azolla so this part of the experiment is taking me a while.