Friday, June 6, 2008

Ants Again

I've noticed in the past few weeks that there are all sorts of new--and really large--ant nests popping up around the property.  Two nights ago, Mary called my attention to a long, LONG double line of ants, streaming across the edge of the concrete pad in front of the dog run.  These were not one of the small, stinging ant varieties, but rather large black ants.  They were headed out in the direction of the bodega.

I hate the stinging ants, but I don't like killing anything unless there's a real need.  These ants were bothering no one, so I decided to leave them alone.

Next morning, there wasn't a sign of them around the house.

After walking the dogs, I headed to the masateras to check on how my lettuce and other veggies were doing.  And found the ants.

They were swarming by the hundreds all over the two raised beds, and seemed to be planning to move into these nice, crumbly soil new quarters.  Then I looked down and saw that I was stepping in (and about to pay a price for doing so) a swarm of black ants that were also headed out towards the ganadera.  Some were even starting to investigate the bodega.

Stamping my feet, swatting and swiping ants (who were biting hard, I might add) off my legs, I pulled out my trusty sprayer from the bodega.  Hating every minute of it, I proceeded to commit ant genocide.  But I left the stream of ants behind the bodega that seemed to be heading for the ganadera alone.  I couldn't tolerate them in the raised beds, but they were perfectly free to make nests elsewhere if they wanted to.

That was Darío's work day.  When he arrived, I asked him why there were so many ant migrations and new nests.  The rainy season, he replied.  Whenever the rains get really heavy, they flood the ant nests, and the ants move out to seek better accommodations.  I asked him about the black ants I'd seen.

I find that most Panamanians who live in the countryside are very environmentally aware.  Darío is one of the most informed, and this time he gave me a fascinating account of these particular ants.  He said that they will "flood" houses at times like this, but that they're valuable because they'll eat cockroaches and spiders.  He had the oddest bright gleam in his eyes when he said "Come cucarachas, come arañas", as he was making hand gestures towards his mouth that typically mean eating.  I swear he was getting some weird sort of kick out of the whole idea.  After imparting that information, he drew himself up to his full height--I'm sure he's at least 6 ft tall--and then gave me a lecture about how no one understands that these ants are part of the ecological balance--and went off into an environmentalist rant.  Darío tends to rant about many things, so I'm used to this.  It's always entertaining and I usually come away with new information.

A few hours later, after he had completed a small project for me--I wanted him to elevate two water shut-off valves we have, one near the ganadera--he was not quite so taken with these ants because sure enough, that swarm I'd seen the night before was rooting around where he needed to work and he was more than a little indignant at their nerve and bites.  I knew exactly how he felt.

I wondered, though, about the ants he'd described.

When we first moved here, we heard stories about the army ants of Costa Rica that did make migrations in their thousands and did sweep through houses.  One man who lived for many years in Costa Rica before moving to Panamá said that he'd seen them there.  He said you could always tell when they were coming because suddenly every bug--roaches, spiders, other ants, you name it--would leave en masse from the house.  He said you never knew how many insects you were harboring in your house until the army ants came through.  Those that couldn't make it out were eaten on the spot.  He said they never bothered humans or other large animals, just insects.

I've never bothered finding out what the different ant species are here, but the story came to mind as Darío was describing the behavior of the ants.  And to tell the truth, there are so many ant species here, that I don't even know if "our" black ant horde was the same as those he talked about.  

So, I did a little Internet research and found out yes, indeed, Panamá does have army ants.  In fact, an island in the Panama Canal, Barro Colorado, a biological reserve where the Smithsonian Institute has a large research mission, has 50 colonies of Eciton burchelli, the most studied and most frequently encountered army ant species (there are over 200 species world-wide, 120-130 in the New World, ranging from Argentina to Mexico).

Despite Indiana Jones and the Kingdom of the Crystal Skull, South American army ants will not bring down and eat Soviet or any other soldiers, other humans, large livestock, or similar animals (sorry to ruin the movie for you).  Some African species might, but not in our half of the world.  They're nearly blind and just simply swarm over, attack, kill and eat any other ant species, scorpions, cockroaches, or other insects that happens to get in their way--even lizards and frogs that don't get out of their way in time, although they don't eat those.  The only way they will attack humans is if you step into them or are having a campout and you and your sleeping bag are in their route.

Their colonies are huge, ranging from 500,000 to millions!  The head of the column is fan-shaped, with a tail of worker ants.  They really don't build any permanent nests, but are migratory, just like human nomads.

Given that there are lots of subspecies of Eciton, it could be that what we saw on Tuesday night and Wednesday were indeed some variety of army ant, although I saw nothing like the pictures of the soldier ants that make army ants so devastating.  Their mandibles are fearsome--long and curved inwards sort of like a pair of scythes.  But I may have happened on the tail end of the column and just met up with the workers.  The soldiers are huge and reddish, while the workers are various sizes and black.  All I ever saw were black ants of varying sizes.  I never did see the head of the column or, for that matter, the actual end.  

Also, I'm not sure that our migrating colony had enough ants to qualify.  I never saw the whole colony but it seemed to me that I was looking at maybe a thousand, not a half million.  The "stream" didn't look enough like what I'd seen on various Web sites and YouTube. I  never saw the classical "bivoac", a mound of these ants whose "wall" is composed of the ants themselves, attaching to one another. Yet, about 6 hours later, there were still black ants in a narrow column wending their way alongside the bodega clearly on their way to the ganadera pasture behind the house. Today they're gone--there isn't a trace of the ants around.

So I really don't know for sure, but am leaning towards the idea that they were indeed army ants.   Rather than building a nest, they may just have been foraging in the masateras.  

I wish I could find non-copyrighted pictures of these nasty little devils in order to post them here, but unfortunately I can't.  Mary is not a terribly squeamish person, but when I showed her some of the more "dramatic", shall we say, pictures of army ants, she went "Euww!  Euww!" and more or less fled.  The Youtube videos I've seen are not the best, and again, I can't really compare.

But still, I learn something new every day about life here.

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