The Gunma Prefecture Museum of History was established in a park in which there are many wild birds and small animals. These tend to enter the museum. In 80 days 471 different insects were collected, including dermestid beetles, clothes moths and spider beetles, all known to damage cultural property. Spraying with Smithion-VP (fenitrothion 5%, DDVP 2%) did not greatly diminish the dermestid problem. Methyl bromide fumigation would be required for eradication. All openings in the museum walls were fitted with screens and double doors at the entrances. Daily cleaning is carried out throughly and visitors are requested not to bring in food. Training on conservation has also been given to museum personnel. Lists of insects found, photographs, plans.