dont bite the hand that feeds you

Dont bite the hand that feeds you is a cliche term which is advising you on not acting against people who you depend on. If someone is feeding you, supporting you or providing you with other types of comfort, security and safety, you should treat them with respect and kindness, rather than biting them as in the phrase, or being ungrateful to them. If you treat someone poorly who does you favors and helps you, they may stop helping you in the future.