It is obviously not possible to exclude animals completely from a house. In most cases the most sensible course will be to hinder the entry of animals and, subject to technical and aesthetic considerations, to deny them suitable living conditions if they do succeed in gaining entrance. Fortunately, such measures will usually also promote general domestic hygiene.
Details on preventive measures have already been discussed in the individual sections of this book, but in general it can be said that all kinds of cracks, crevices and inaccessible spaces are highly undesirable, particularly in kitchens and canteens, for they allow the accumulation of dirt and the multiplication of pests where they will be most difficult to control.
Although the complete exclusion of all animals from a house is virtually impossible, certain simple measures such as fitting netting over doors and windows may be effective in keeping out flies, mosquitoes and wasps.
On a more technical level, insects can be excluded by a so-called air curtain. This involves setting up a current of air through which the insects cannot pass,
Practically speaking, all insects and mites thrive best in places with a high humidity and relatively high temperature. Dry, cool storage of foodstuffs and cleaning without the excessive use of water are therefore indicated.