Moed Katan 1:4-5
Moed Katan 1:4
It is permitted to trap moles and mice in a field of trees or grain on chol hamoed and during the Sabbatical year, though not in the usual manner; the Sages maintain that they may be trapped in the usual manner in a field of trees and in an unusual manner in a field of grain. One may repair a breach in his fence during chol hamoed and build in the usual manner in the Sabbatical year.
Moed Katan 1:5
Rabbi Meir says that kohanim may examine leprous signs for the first time on chol hamoed in order to be lenient (i.e., to declare the person ritually clean) but not to be stringent; the Sages say this may not be done on chol hamoed, neither to be lenient nor to be stringent. Rabbi Meir said further that one may gather his parents’ bones (on chol hamoed, for reinterment) because it is a form of joy (to bring them to rest in the family plot); Rabbi Yosi says that it causes one to mourn. One may not arouse dirges or eulogize for his dead for 30 days before a festival.