Many acts of seeming sabotage have been committed by our furred, finned, and feathered perhaps non-friends over the years. Are they publicity ploys? Protests against human hegemony? Or just accidental run-ins inevitable given the extent of mankind’s enterprise and infrastructure? You be the judge.  

1. MARTEN vs. LARGE HADRON COLLIDER

Though initially identified as a weasel, it was actually a beech marten that short-circuited an electrical transformer at the European Organization for Nuclear Research (CERN) on April 29. When the marten leapt onto the open-air transformer, it created an electrical arc that damaged high-voltage transformer connections and cut power to part of the Large Hadron Collider, according to a CERN press release. Repairs to the transformer connections went without a hitch, though, and the world’s largest and most powerful particle accelerator has been able to proceed with its 2016 physics season as planned.

2. SQUIRREL vs. STOCK EXCHANGE

Among the “notable shut downs” on the Wall Street Journal’s 2013 list of stock exchange stoppages are “Squirrel I” and “Squirrel II.”

In December 1987, an “adventurous squirrel” caused a power failure in Trumbull, Connecticut, then the site of the NASDAQ’s main computer center. Even after Trumbull’s power was restored, damage to the NASDAQ’s electrical system necessitated a switch to its backup system in Rockville, Maryland, so all told the rodent shut down the exchange’s automatic quotation service for 82 minutes, thereby decreasing trading by an estimated 20 million shares. A similarly squirrel-induced stoppage—that would be Squirrel II, a 34-minute interruption—occurred in August 1994.

For more on squirrelly assaults on the power grid, check out “Squirrel Power!” by Jon Mooallem.

3. JELLYFISH vs. NUCLEAR POWER PLANT

In October 2013, in what The New York Times’s Dan Bilefsky described as “an episode that evokes B-grade sci-fi movie plots from the 1950s, but actually reflects a continuing global problem,” a swarm of moon jellyfish clogged the cooling water intake pipes of the world’s largest boiling water nuclear reactor. The jellies entered the pipes 60 feet beneath the surface of the Baltic Sea, where Sweden’s Oskarshamn nuclear power plant draws the cold water needed to cool its reactor and turbine systems. The intruders did not breach the plant’s filters or approach the reactor itself, but their incursion nonetheless forced a temporary shutdown of the facility’s Unit 3.

Nor is the Oskarshamn incident an isolated one. Oskarshamn itself experienced a similar jellyfish clog in 2005 and, as Discovery News reported, jellies have gummed up nuclear power generation from the Philippines to Florida.

4. EEL vs. WASTEWATER TREATMENT PLANT

Process control supervisor Ray Weaver had seen a lot in his 20 years at Manchester, Connecticut’s wastewater treatment plant, but never anything as big as what was jamming a pump there in October 2011. When Weaver’s coworker removed an elbow-shaped section of pipe, out flopped a 32-inch-long eel, 2 inches in diameter.

5. SLUG vs. TRAFFIC LIGHT

Traffic has been snarled by koalas and free-range chickens and seas of sheep. Also, at least once, by a wayward slug. In 2011, engineers in Darlington, a market town in northeastern England, dismantled a traffic light control box that had ceased to function. On the circuit board inside they found ... fried slug. "Somehow the slug managed to infiltrate the control mechanism, sit on the circuit board and then it got, well, fried," Chris McEwan, a member of the Labour Council, said. "We don't know how long it had been there. Unfortunately, it was dead by the time we found it, so we were unable to question it. Sadly, you just can't legislate for a rogue slug trying to take out Darlington's traffic system."

6. DOGS vs. AIRPORT

The dogs running loose in Tokyo’s Haneda Airport earlier this month may not have captivated the internet like the pair of therapy llamas that became social media sensations in February 2015, but the canines caused a greater disruption. By preventing landings, delaying takeoffs, and even prompting destination changes, the presence of the four strays disrupted the operations of at least 18 flights into and out of Japan’s capital. Since fences nearly 10 feet high enclose the airport, officials were unsure how the dogs got in. Video footage shows them lolling in the grass and trotting across the tarmac, seemingly oblivious to efforts by airport employees to clear the runways.