What is Be Bugging?

In simple words, "Be bugging" is the process of adding known defects to the application by seeding.
Or
The process of intentionally adding known defects to those already in the component or system for the purpose of monitoring the rate of detection and removal, and estimating the number of remaining defects.
Or
If the Project management add some known defects in order to estimate the efficiency of tester, then it is called Be bugging or Defect Seeding or Defect Feeding.

What is Test Harness?

In software testing a test harness or automated test framework is a collection of software and test data configured to test a program unit by running it under varying conditions and monitoring its behavior and outputs.

It has two main parts: the Test execution engine and the Test script repository.
The typical objectives of a test harness are to:
(i) Automate the testing process.
(ii) Execute test suites of test cases.
(iii) Generate associated test reports.

A test harness may provide some of the following benefits:
1) Increased productivity due to automation of the testing process.
2) Increased probability that regression testing will occur.
3) Increased quality of software components and application.

What should a test harness include?
Test harnesses should include the following capabilities:
i) A standard way to specify setup (i.e., creating an artificial runtime environment) and cleanup.
ii) A method for selecting individual tests to run, or all tests.
iii) A means of analyzing output for expected (or unexpected) results.
iv) A standardized form of failure reporting.