What do you call a creature that looks like a miniature lobster and generally lives in lakes and streams? If you’re in New England, you might go with “crayfish.” On the west coast of America, probably “crawdad,” and in the South, “crawfish.”

If you’re in Germany, though, you might call them something else: unwelcome!

As DW.com reports, invasive American cray/craw/fish/daddies have been creating a “crayfish panic” in one of Berlin’s largest public parks, Tiergarten, this summer, “scuttling around the paths” and “even parading outside the neighboring Spanish Embassy.”

The species in question—the Louisiana crawfish, or Procambarus clakrii—isn’t supposed to be in Germany at all: the country has its own native types, which can be displaced or sickened by these newcomers. But they’re a popular home aquarium pet, and Germany’s Nature and Biodiversity Conservation Union (NABU) suspects that they arrive in the park when people tip their tanks out into the ponds there, writes DW.com. (In 2014, they showed up in a swimming pool in Frankfurt, likely for a similar reason.)

The crayfish have thrived in their new home, and are now likely “trying to expand their territory,” the outlet writes. As the Local reports, recent heavy rains are also driving them out of their streambank holes.

Now that they’re there, there’s no easy way to get rid of them: poaching laws forbid people from catching them, which nixes the potential for a nice German crawfish boil.

So NABU finds itself a bit stuck. The organization is currently fielding daily calls about the crustaceans. Pedestrian and joggers are also reporting sightings in a more public way, on Twitter.

“Just stumbled upon a whole bunch of crayfish sneaking around in the middle of the night,” one posted in late June. Just two weeks later, they’d grown bolder: “Ambushed by a gang of crayfish,” another park-goer wrote on July 10th. That’s crawfish to you, bucko.

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