Start with the figures on the left hand side of the key. The bracket alongside each of these figures encloses 2—4 choices. Select the most suitable alternative. Your choice leads either to a new figure or directly to a species or an animal group. The keys are based entirely on external characters, which can be seen with the naked eye or with the help of a lens giving a magnification of c. 5 times.
Naturally one may make a mistake and must then start again. It is a good idea to use the plates as an aid when using the keys.
In view of the nature of the material these keys are naturally very approximate. It is no use taking them out into the fields or woodland, for they have been designed exclusively for the identification of animals commonly found indoors.
"Pests in House and Home"
"Bed Bugs - Bites, Stings and Itches"
"Food Pests"
"Husets dyreliv" (Insects Around the House - Only danish)
"Skadedyr i træ" (Timber Pests - Only danish)
"Stuefluen" (Common Housefly - Only danish)