# The Ounce: Spring Pests Have Sprung April 17, 2025 Welcome to The Ounce, an occasional missive for Harvard Library colleagues from Preventive Programs in HL Preservation Services. Spring has sprung and with it an increase in pests. With this uptick in activity, Preservation usually receives the following questions: What is this bug? Should I be concerned about it damaging library collections? ## Preliminary Pest Identification Because we are [Champions of Curiosity](https://library.harvard.edu/visit-about/about-harvard-library#:~:text=At%20Harvard%20Library,%20we%20are,world%20knowledge%20and%20intellectual%20exploration.), and the quality of phone-based photo ID applications has improved, many may begin researching a bug on their own. If you choose to pursue this path of inquiry, remember to use trusted sources like those provided by [Environmental Health and Safety (EH&S)](https://www.ehs.harvard.edu/programs/pest-control) or [MuseumsPests.net](https://urldefense.proofpoint.com/v2/url?u=https-3A__museumpests.net_newimagegallery_&d=DwMFAg&c=WO-RGvefibhHBZq3fL85hQ&r=TOalLLoN60oCD9_1iA5loUqugNxEnlM05OXAnqizmlg&m=kGc0mIIWcFIeOztF4H8u1hhO5nKFU-U4Uej86Cqr7WsDmB_E2sISOhtCb8yiW1C6&s=BXpQNr5sN0kKM1Hei4m04ZwXAz1IebDhwkfAipscTPU&e=). Preliminary pest research is not a requirement. We encourage you to request assistance from EH&S or Preservation Services if desired. Many of the springtime pests observed are not a high risk to library collections, but they should still be reported as part of your library’s [Integrated Pest Management (IPM ](https://www.ehs.harvard.edu/sites/default/files/ipm_harvard_university_museums_libraries_and_conservation_preservation_facilities_overview.pdf)) process so that their numbers can be monitored. ## The Dirty Dozen Higher risk insects for libraries and museums are known as [The Dirty Dozen](https://urldefense.proofpoint.com/v2/url?u=https-3A__museumpests.net_wp-2Dcontent_uploads_2015_04_Insects-2DLImited-2DMuseum-2DDirty-2DDozen-2Dsingle-2Dsheet-2DA4.pdf&d=DwMFAg&c=WO-RGvefibhHBZq3fL85hQ&r=TOalLLoN60oCD9_1iA5loUqugNxEnlM05OXAnqizmlg&m=kGc0mIIWcFIeOztF4H8u1hhO5nKFU-U4Uej86Cqr7WsDmB_E2sISOhtCb8yiW1C6&s=MU2Nelzpope8a7Zc2PboDTp5-hUcpLrY1WLOy0WU69w&e=). Of particular interest are those that favor paper-based collections, which often make up the majority of library and archival holdings. These include[: book lice](https://urldefense.proofpoint.com/v2/url?u=https-3A__museumpests.net_wp-2Dcontent_uploads_2018_08_book-2Dlice.pdf&d=DwMFAg&c=WO-RGvefibhHBZq3fL85hQ&r=TOalLLoN60oCD9_1iA5loUqugNxEnlM05OXAnqizmlg&m=kGc0mIIWcFIeOztF4H8u1hhO5nKFU-U4Uej86Cqr7WsDmB_E2sISOhtCb8yiW1C6&s=WMU88_d5vDZsTg5hlfAw8eh02415wdRpFOjYyW98y5A&e=), [cockroaches](https://www.ehs.harvard.edu/sites/default/files/cockroaches_reporting_response.pdf), [mice](https://www.ehs.harvard.edu/sites/default/files/mice_faqs.pdf) and [silverfish](https://urldefense.proofpoint.com/v2/url?u=https-3A__museumpests.net_wp-2Dcontent_uploads_2019_06_Gray-2DSilverfish-2D6-2D7-2D19.pdf&d=DwMFAg&c=WO-RGvefibhHBZq3fL85hQ&r=TOalLLoN60oCD9_1iA5loUqugNxEnlM05OXAnqizmlg&m=kGc0mIIWcFIeOztF4H8u1hhO5nKFU-U4Uej86Cqr7WsDmB_E2sISOhtCb8yiW1C6&s=GvUXGQU58H2iJ2gZDSyATEK85DLwknCbe2KGEqjrskw&e=). We are also concerned about [webbing clothes moths](/blog/ounce-do-flight-thing-how-combat-webbing-clothes-moths-collections). In general, prevention of the Dirty Dozen can be achieved through securing foods, maintaining good sanitation practices, keeping windows and doors closed, monitoring and reporting pests and pest activity, as well as cooperating with the pest control vendor and maintaining a humidity of 55% or lower when possible. ## Further Assistance If you want help assessing the risk of a pest to library collections or working with your building manager to set up an IPM program for your library, please [contact Preventive Programs](mailto:HL_PrevProInquiries@HU.onmicrosoft.com). Share on:- [ Facebook ](#) - [ Twitter ](#) - [ Linkedin ](#)