to remain silent or hold oneself aloof in a sullen, ill-humored, or offended mood: Promise me that you won't sulk if I want to leave the party early. a state or fit of sulking. sulks, ill-humor shown by sulking: to be in the sulks. Also, sulker. a person who sulks.
Some cite the fact that secretions from the millipede repel other insects as a reason why they are beneficial. While millipedes do not bite, the sight of them can still be unnerving, especially when they appear in large numbers. They have the ability to crawl up walls and enter homes through small openings.
Also most millipedes are nocturnal. They are generally speaking harmless but most species have a series of metathoracic glands which produce a repellent substance which they can exude when they feel threatened. In some larger species this fluid can be corrosive and cause blistering of the skin in large doses.illipedes are generally considered to be harmless but they can be pests in some circumstances. In Europe sugar beet is the main crop to suffer from millipedes. In Africa Spirostreptids can be damaging to cotton and groundnuts.