[robotresearcher]

It does. The article says: "Garnier’s study helps to explain not only how unorganized ants build bridges, but also how they pull off the even more complex task of determining which bridges are worth building at all."

The final quote is from another researcher in a reaction quote about army ants. It's not clear what the context this other researcher has in mind. Of course 'they aren't as simple as we might think' is a pretty safe guess.

Here's the meat:

"To see how this unfolds, take the perspective of an ant on the march. When it comes to a gap in its path, it slows down. The rest of the colony, still barreling along at 12 centimeters per second, comes trampling over its back. At this point, two simple rules kick in.

The first tells the ant that when it feels other ants walking on its back, it should freeze. “As long as someone walks over you, you stay put,” Garnier said." [the 2nd rule is less explicitly stated, so you need to read the article to get a sense of it]

[bvod]

"'We’re trying to figure out if we can predict how much shortcutting ants will do given a geometry of their environment,' Garnier said." Garnier clearly states that they haven't figured out the algorithm. Then the separate researcher says “We describe army ants as simple, but we don’t even understand what they’re doing"

[robotresearcher]

Then we disagree about what 'the algorithm' means. They have a bridge-building method, but can't reproduce the ants' decision on where to place them. Place the emphasis where you like to decide if they succeeded or failed.