So you've been invited to a kräftskiva. Now what? Kräftskivor - or crayfish parties - are arguably Sweden's most festive annual excuse for a party.
It's an August craze and perhaps the messiest party you have been to since you were six years old and left birthdays with cake smeared around your chops.
While there are multiple variations of how to celebrate the crayfish season, there is invariably one ingredient in every single party: the crayfish.
The rest of the party's ingredients include ample aquavit or snaps, crisp bread, ample aquavit or snaps, cheese, paper lanterns, funny hats - and ample aquavit or snaps.
And everything and anything crayfish-related belongs to the fun. If it's used on the day, Swedish shops will sell it with a crayfish printed on it. Decorations, lanterns, tablecloths, glasses, plates - indeed, complete serving sets - will all be adorned with the little red crustacean.
Up until 1993 the sale of crayfish was restricted to after August 8th. But with Christmas beginning in October (in retail terms at least) nothing is sacred, and crayfish are now on sale year round.
In addition to crayfish commanding their own seasonal display in every store, they also have a history, a mythology and a modern PR campaign.
Eating crawfish - and they have many dialectal names in English - goes back to the time of King Erik XIV in the 16th century. His highness was known to have farmed the crusty crawlers in his moat at Kalmar Castle. The native species in Sweden, flodkräfor, are generally referred to as the noble crayfish.
It was the end of the 19th century when the current tradition of eating crawdaddies whole, cold and basking in the dill weed water they were boiled in began. That was an age when it became popular to send off the summer sitting on verandas or out in the garden while quietly cracking a shell.
The party came soon after. The Swedish name for the party, kräftskiva, first entered the language in the 1930s.
It hasn't been smooth sailing for the little mudbugs. Swedish flodkräftor were threatened in 1907 when the crayfish were first afflicted by crayfish plague. It seemed like the noble Swedish crayfish would soon become extinct.
The American cousin, the signal crayfish, was introduced in a belief that they were resistant to the plague and could replace the dwindling Swedish noble variety.
According to the Swedish Environmental Protection Agency (Naturvårdsverket), recent research, has shown that the introduction of the Yankee cousin was a big mistake. It's now known that once the plague has killed off the local lake's population, the plague eradicates itself. With the resistant variety, the plague lingers on and slowly spreads.
The mythology and PR
A few years ago the Swedish Environmental Protection Agency sponsored a PR campaign to debunk the misconceptions of the little yabbies' fate in an attempt to come to their rescue. Their web site (in Swedish) busts the myths many people have about fresh water mini-lobster.
Its focus seems devoted to discouraging people from stocking waters with the non-native variety. The research shows that true demise of the noble variety is inevitable if the signal crayfish continues to proliferate either naturally or with help from hungry Swedes eager for free fodder for the kräftskiva.
Which brings us back to the invitation and what you need to know when invited.
The kräftskiva is a truly fun party to attend or throw. Guests often come equipped (often at the host's request - like a pot luck dinner) with their own supply of spoondogs and their own booze.
The host need only supply the crayfish-bedecked paraphernalia, the crisp bread, the cheese and the ubiquitous sauna. So if you are lacking an invitation it's time to send some out yourself.
Whether you're going or throwing, don't start the party hungry. It takes about 5 minutes to dig out the eqivalent of about a meatball's worth of meat.
In that time you will be required to pause, hold up your snaps glass, fake your way through the song and throw back a shot. You don't want to have an empty stomach. (For the same reason, don't go drunk.)
Don't be embarrassed to ask for instructions in the dissemination of the little mudbug. There are a number of approaches which usually begin with ripping off the head, breaking back the legs and slurping the underbelly. The operation concludes with cracking open the claws for the delicate pink-white flesh inside.
Passing the test
If you want to impress Swedes in attendance, there are a few measures which will be used to determine your performance.
Your gusto will be rated by the volume of your slurping, the stickiness of your fingers and the quantity of shells stacking up - or lined up - on your plate.
And, of course, by the enthusiasm with which you belt out the theme song, Helan går.
Sjung hopp faderallan lallan lej
Sjung hopp faderallan lej
Och den som inte helan tar
Han heller inte halvan får
Sjung hopp faderallan lej