Germany's alpine huts deploy dogs and microwaves to beat bed bugs

Trained bedbug detector Linus is snuffling along the wooden skirting boards in an alpine hut, before turning to the bed.

Linus is seeking out any bugs that could disturb hikers resting in the Bavarian hut.

He is a mixed-breed, trained to track down bedbugs. Today Linus has been deployed to the German Alpine Club's (DAV) Schneibsteinhaus, perched at an altitude of 1,670 metres in Berchtesgaden National Park, as part of the annual bedbug prevention check.

Dogs can sniff out the bloodsuckers which often hide in cracks and behind wooden panelling, places a hut warden wouldn't think to look, even during a meticulous search using a head lamp.

What do bedbugs smell like?

Linus did not detect anything suspicious. But to give him a sense of achievement nonetheless and the treat he yearns for, his handler, Laura Pannasch, hid small tubes containing real bedbugs.

She also strew some scraps of paper round the room sprayed with "bedbug perfume" that she made using dead bedbugs preserved in alcohol. It smells slightly sweet like bitter almonds.

Bedbugs have been a concern for the DAV for years. Hikers unwittingly bring in the insects travelling in their rucksacks, sleeping bags or clothing.

Germany has a network of mountain huts designed for hikers exploring the mountains, whether the peaks of Bavaria, the Black Forest or the rocky formations of "Saxon Switzerland." The huts themselves vary from taverns to multi-day alpine bases.

Most provide local dishes, affordable beds in dorms plus stunning vistas.

But wherever large numbers of people sleep in different beds, that is ideal for the insects.

No one knows how many bedbugs there are around as places affected often prefer to keep quiet about them. No one wants their home to be associated with vermin, after all.

Guests need to play their part

"Find Wolli," says Pannasch as Linus sniffs his way through the dormitory. "Wolli" is her code word for bedbug and she has trained Linus to recognize it.

Pannasch also has clients down in the valley. There, she often has to use the back entrance when she comes with Linus so guests don't realize they are searching for bedbugs.

The DAV stands relatively alone with its open approach. Every year, around 15 to 20 of the approximately 325 DAV huts are affected, the association reports, with the numbers rising.

That is likely partly due to the growing popularity of mountain sports, with rising numbers of overnight stays. Some 900,000 people slept in alpine huts in 2024, the DAV says.

Here at the Schneibsteinhaus, notices about the bedbug problem are displayed at the entrance, in the stairwell, in the rooms and even in the toilets. The landlady is asking visitors to not take their rucksacks – which act like "bedbug taxis" – into the rooms and to use the sleeping bags provided by the hut.

Hut warden Stefan Lienbacher says that the problem can only be tackled if guests are aware of it and help out.

Expensive bedbugs

Costs rise once bedbugs enter buildings. The pest control service costs around €20,000 ($22,800), says Gabi Schieder-Moderegger, chair of the Berchtesgaden section of the DAV, to which the Schneibsteinhaus belongs.

However, other departments say costs can rise to €50,000. Using a sniffer dog costs around €500 to €2,000, depending on the size of the hut.

Staff at the Schneibsteinhaus well remember the infestation three years ago when a guest reported bites. Fortunately, before the bugs spread through the whole hut, Lienbacher managed to call in a pest control expert, who heated the infested mattresses to 60 degrees Celsius, using a sort of tent.

Not mountain creatures

Section chairwoman Schieder-Moderegger came along for a test sleep afterwards and reported no bites. The operation was a success.

People often felt guilty in the past if bedbugs were found, asking themselves, "Is it my fault? Have I done something wrong?" But it can happen to anyone, Schieder-Moderegger says, adding ultimately, the problem began down in the valley. As DAV spokeswoman Miriam Roth puts it: "The bedbug is not a mountain creature."

The brown insects, measuring just a few millimetres, feed on human blood: their bites can be very itchy but are not dangerous. "Bedbugs do not transmit diseases. It's simply a nuisance," says mountain hut owner Lienbacher.

Bedbugs are also not a sign of bad hygiene. Cleaning products have no effect on bedbugs. "There's no home remedy for it; you need professionals who know what they're doing."

Light blue duvets and white sheets

To spot an infestation faster, the Schneibsteinhaus and other huts have altered their colour schemes. They now use light blue duvets instead of brown ones. "We've also replaced the bed sheets; they used to be dark, now they're light," says Lienbacher. "That makes it easier to spot traces – bloodstains, faecal stains, moulted skins – more quickly."

Microwave helps

Each hut is different and takes its own approach. The Rotwandhaus has a rule that personal belongings may only be brought into the room in plastic boxes. Hut sleeping bags must be put in the microwave at check-in. They are heated for 30 seconds at 600 watts. Other huts too use this kitchen appliance to handle creepy-crawlies.

The risk of bedbugs is highest on popular long-distance hiking trails, where you move from hut to hut. The section has such huts treated preventatively twice a year, says Carolin Kalkbrenner, head of the Huts & Trails department at the Munich section. But, she notes, "the most important thing in combating bedbugs is the cooperation of our guests."

Some hikers prepare each year in case of bedbugs. Franz-Josef Hofmann boils the sleeping bags used in the hut. "Arrive clean, don't bring anything in" is the first step, he says.

They've heard about bedbugs, say other guests and aren't sure how best to respond. "Spray?" suggests one visitor tentatively.

In fact it is easy. The advice is to empty your rucksack over the bath, wash your clothes at 60 degrees, or freeze them for three days at minus 18 degrees.