Wood-Destroying Organism (WDO) Inspection Course

Welcome to InterNACHI's free, online Wood-Destroying Organism (WDO) Inspection Course. 
Take the free, online course now.
Order the WDI Inspection Field Guide.
Download the free WDO Form and Inspection Guide.
This course teaches the inspector how to inspect for indications of infestation of wood-destroying organisms that may exist in a building using a visual-only examination.  
Upon successful completion of this course, the student will be able to:
  • describe and sketch the biological aspects of common wood-destroying organisms;
  • identify and describe termites, fungi, and common wood-destroying insects;
  • communicate treatment and management options for wood-destroying insects;
  • methods to prevent termite damage;
  • inspect crawlspaces; basements; and foundation structures by following an inspection checklist and WDO form;
  • list the critical laws concerning wood-destroying insects; and
  • describe the value of the inspection in relation to the real estate transaction. 
Course includes:
  • 127,448 words;
  • 6 minutes of video; 
  • student book;
  • inspection and writing assignment;
  • research and writing assignment;
  • 85 quiz questions over 10 quizzes;
  • 100-question final exam (drawn from a larger pool);
  • instant grading; and
  • a downloadable, printable Certificate of Completion.

Wood-Destroying Organism Inspection Course

Course # 3406




Estimated hours for the average student

Academic Engagement

Reading online course instructional material at 140 words per minute


Watching and listening to instructional video


Taking quizzes


Taking the exam


Conducting a directed and independent inspection study performed according to the Standards of Practice, including the development of an inspection report 


Submitting an inspection and writing assignment


Submitting a research and writing assignment





Studying and reviewing instructional material in preparation for taking quizzes and exam


Reading the downloaded student course book including taking the quizzes with the book


Reading, research, and studying related to completing the research and writing assignment
 Studying and preparing for inspection processes according to a Standards of Practice, including capturing and storing digital images with a camera or device, making observations, evaluating conditions, deducing, formulating opinions, communicating observations in written form, attaining competency in performing inspections and using an inspection checklist or software and other inspection tools in producing a report.



Sub Total


Overall Total

70.0 hours / 1.7 SCH

And, in keeping with InterNACHI's commitment to Continuing Education, this WDO Inspection course is free to all InterNACHI members, and can be taken again and again, without limit. 
Reminder to members:  InterNACHI's Code of Ethics 1.10 requires that you comply with all government rules and licensing requirements of the jurisdiction where you conduct business.  InterNACHI's courses and Standards generally exceed the Standards of Practice that you are required to abide by locally. 
This course has been approved by:
The course covers the following categories:
  • Preface
  • Introduction
  • Biology
  • Termites
  • Subterranean Termite Treatment
  • Pesticides for Termite Control
  • Bait, Foam and Fumes
  • Treatment of Crawlspaces 
  • Treatment of Basements
  • Other Treatments for Termites
  • Application Equipment
  • Contamination of Drinking Water
  • Sample Calibration Problems
  • Other Wood-Destroying Insects
  • Management Options for WDI
  • Preventing Termite Damage
  • Wood-Inhabiting Fungi
  • Understanding Foundation Structure
  • Inspecting Structures
  • Inspection Checklist
  • Basic Construction Terminology
  • Laws Concerning WDI
  • Training and Licensing
  • The Real Estate Transaction
  • Completing NPMA-33 Form
  • References and Study Material
  • Glossary
  • Bibliography
Upon completion of this course and passing of the 100-question final exam (drawn from a larger pool), the student can download and print their own Certificate of Completion which is auto-generated in their own name. 
The student's (InterNACHI member's) information is recorded on InterNACHI's servers for membership compliance verification, and automatically logs completion into InterNACHI's online Continuing Education log.
Non-members may view only the first page of the course.
Members will need their username and password.  If you have forgotten your password, CLICK HERE (instant response) or email fastreply@internachi.org and request it (don't forget your name). 
InterNACHI... #1 in inspection education. 
Other inspection courses.
Some features which make InterNACHI's courses superior to existing continuing education options:
  • The course is free for all InterNACHI members.
  • The course is written in pure XHTML code for quick loading.  The course loads fine on old computers and loads fast, even with dial-up.
  • The course is designed using a hierarchal menu coupled with a sequential page navigation.  This provides the student with the option to easily repeat areas of weakness.
  • The course permits the student to start, stop and restart any part of the course as often as desired.
  • There are a variety of images within the course, including diagrams, illustrations and photos. 
  • The illustrations can be enlarged for clearer viewing by clicking on them.
  • The text is integrated into InterNACHI's Inspector Glossary.  Rolling over blue-colored terms provides their definition.
  • The final exam uses multiple-choice questions that reference the images. 
  • The course's quizzes and final exam have numerous advantages over traditional exam systems:
    1. The course, quizzes and final exam incorporate built-in intelligence which identifies and strengthens each student's unique subject weaknesses.
    2. Not only is each question weighted with regard to score, but each answer is weighted, as well as the correctness of each answer being weighted.
      1. Answers to easy questions are weighted such that the student is penalized, in terms of score, for answering incorrectly, but rewarded modestly for answering correctly.
      2. Answers to difficult questions are weighted such that the student is rewarded, in terms of score, for answering correctly, but not penalized for answering incorrectly.
      3. Answers to questions regarding basic safety, or questions every inspector should know the answer to, are weighted such that the student is severely penalized, in terms of score, for answering incorrectly.
  • Upon passing the final exam, the student can print out a Certificate of Completion which is auto-generated in their own name.
The student's (InterNACHI member's) information is recorded on InterNACHI's servers for membership compliance verification, and automatically logs completion into InterNACHI's online Continuing Education log.
For TEXAS Students:
Provider License #:10026
Course Approval #:31286
Why online inspector education is better than classroom inspector education.
Download the WDO inspection report form.

WDO Insect Inspection Guide (free download):