I cleaned up their container because it was choked with silk. They seemed kind of sulky afterwards, but look, clean soil, and I propped up a clam shell to give them a nice shelter. What did they do? They coated everything with silk! I can’t even see into their hiding space because the silk is nearly opaque!

I think the evidence is clear that they’ve entered their spider teens: sullen and sulky, their room is incredibly messy, and they really want their privacy.

We don’t have air conditioning, which means we don’t have the house buttoned down tight in the summer, which means the occasional fly wanders in and heads to the kitchen, always the kitchen. But they don’t last long, because we’ve got a tangle of cobwebs under our cupboards, which are occupied by fierce fly-killers. This is a Pholcus phalangioides caught in the act of ‘explaining’ to a housefly that we don’t care for their kind comin’ round these parts.

I didn’t notice the teeny tiny gnat snared in the web by the spider’s hind leg when I took the picture.

You probably assume you can recognize black widows by the red hourglass on the underside, like this:

But the juveniles and other variant forms can look like this:

And you might as well give up, because in their natural environment they may not pose obligingly for you.

Those are all young’uns, the spawn of the few adults I got this summer. They’re thriving!

The headline says, “Giant spiders the size of rats make comeback in UK after nearing extinction, RSPB says“. Nah, I know these spiders. That’s Dolomedes. We call them fishing spiders here in the colonies.

Fen raft spiders starting to appear on the Dyke networks of the Lower Waveney Valley. This one was battling the wind even on this sheltered Dyke line. @suffolkwildlife @WaveneyCott @BBCCountryfile @HeritageFundM_E @SWTCarltonMarsh pic.twitter.com/pbMh8oGC2W

— Suffolk Wildlife Trust North East Reserves (@SWT_NE_Reserves) April 9, 2024

They are large spiders, but not as big as rats…unless you’ve got nothing but stunted, runty, starveling rats out there in the UK, scarcely big enough to put onna stick.

I’m surprised that they (the spiders, not the rats) were endangered — they seem to be doing fine here, in a part of the country with lots of wetlands that get some protection (but not enough) because they’re a haven for game birds. It’s good to hear that Dolomedes is making a comeback, though, in part because the zoos are raising more spiders.

That looks familiar, that’s how I raise my spiders. I hope they have many more vials than that, if they’re hoping to repopulate the whole of Britain.

I don’t think even minuscule UK rats would fit in those vials, you know.

I am a cruel and terrible spiderlord. I have just been overwhelmed with these black widows, which are awesomely fertile. The two adults I have just produced two more egg sacs! There’s a hundred spiderlings in each, and every few weeks another sac erupts and produces a spiderling swarm! I have limited capacity to incubate the horde (although I am getting another incubator from a colleague soon), and also, these are black widows — I have to be careful to prevent any escapes onto campus.

My horrible solution so far is to take advantage of the fact that I have the mothers in a large cage with lots of room for the sprawling horde, and I go in and scoop out a lucky few spiderlings to live in separate vials, and, terrible as it sounds, leave the rest to die. Or maybe die. I’m a softie, so I do shake out a bunch of fruit flies into the container — but not enough to feed a population of hundreds. I figured that eventually they’d winnow down to manageable numbers without any intervention on my part.

I did not take cannibalism into account.

What I’m seeing is that there’s an unexpected distribution of spiderling sizes. The majority are tiny, some are getting large, and a few are getting to sub-adult size. What are they eating? Sure, I’m throwing in some fruit flies, but not really enough to plump up a lot of adults. Therefore, the bully spiderlings must be killing and eating their smaller peers, and growing to a larger size that allows more bullying and sibling murder. Conceptually, it’s a bit horrific.

Today I broke down and decided to distract the bigger spiderlings with a larger, non-conspecific meal, and gave them some mealworms.

The mealworm is in the center, and looming over it with a massive leg span is the young Flashman of this mob, dining on this lovely non-arachnid flavored meal. You can also see the cloud of small juveniles all over the place.

This is not my ideal solution. In the future, I’d like to isolate each egg sac as they’re produced, and control the population more precisely, but I can’t do that now. There’s a new egg sac in this container right now, but it’s in the middle of a tangle of sticky cobwebs, guarded by a fierce mama spider, and to get to it I’d have to stick my hand into this scurrying mass of spiderlings. I’m not worried about getting bitten, but more concerned that I have to make sure no one escapes.

I am aware that this is actually a good problem for an evil spiderlord to have.

I finally got away this afternoon to check on the spiders in the lab, and behold…one of the black widow egg sacs has popped!

Close-up of a Latrodectus mactans spiderling:

At this age, they aren’t noticeably black, more of a reddish orange.

I was struggling to isolate the babies. What made it hard is that a) half of them looked up and saw freedom and rushed to disperse into the general environment of the science building, and b) the other half saw danger in that guy with the paintbrush trying to scoop them up and dived down into mama’s dense tangle of silk. I compromised and spent an hour plucking ballooning spiders out of the air, and left the rest where they were hiding. I’ll be back tomorrow to see if I can catch ’em all — black widow silk is tough and hard to break through.

Also, funny thing — when I left last week, I had 5 egg sacs, then when I got back, one had hatched, but I still had 5 egg sacs. I may have stumbled unto an algorithm for infinite spiders.

First thing I found: a cross orbweaver, Araneus diadematus. We haven’t found any of these where we live in Minnesota.

These are the common spiders both my wife and I remember from our childhoods.