The bug algorithm family is the well-known navigation algorithm for robots in unknown environments. However, different types of bug algorithms have their own priorities and weaknesses based on different environmental conditions. According to the characteristics of the bug navigation algorithms, the bug algorithm family is mainly divided into 4 parts. In this paper, four types of bug algorithms (original bug algorithm, M-line Bug, Angel Bug and Range Bug) are presented along with typical samples of each type. Each type of algorithm will be thoroughly explained and exemplified, highlighting its unique characteristics and the suitable environmental conditions for each algorithm. By presenting the basic logic behind each algorithm and examining the environmental conditions they are best suited for, this paper aims to provide researchers with a comprehensive understanding of the bug algorithm family. Ultimately, this knowledge will contribute to the advancement of navigation capabilities in robots operating in unknown and challenging environments.