Popularly known as the Karni Mata Mandir, this temple is the most called upon tourist attractions in Bikaner. The temple is dedicated to Karni Mata, who the locals believe is an incarnation of Goddess Durga, the protective Mother Goddess in Hindu religion. Karni Mata was a Hindu warrior sage from the Charan caste, who lived in the fourteenth century. Living the life of an ascetic, Karni Mata was highly revered by the locals and earned many followers too. Having received requests from the Maharajas of Jodhpur and Bikaner, she even laid the foundation stones of the Mehrangarh and Bikaner Forts. Although there are many temples dedicated to her, this temple in the town of Deshnoke at a distance of 30 kilometers from Bikaner is the mostly widely recognized.

The Karni Mata Mandir in Bikaner is popular not for its location or architecture, but for being home to over 25,000 rats that inhabit and freely meander around the temple complex. These creatures can be seen emerging out crevices in the walls and floors, often passing over the feet of the visitors and devotees. Consuming food items that have been nibbled on by these rats is in fact regarded as a holy practice here. People from different corners of India and abroad come to witness this astounding spectacle and also bring milk, sweets and other offerings for these sacred beings. Out of all the rats, white rats are held specifically sacred as they are believed to be the incarnations of Karni Mata and her sons. Visitors put in enormous efforts to draw them out often through offering of sweets. However, hurting or killing a rat, even by mistake, is a serious sin in this temple. People perpetrating this crime will have to replace the dead rat with one made of gold, as penance.

Besides the unique customs, the Karni Mata temple also has intriguing legends associated to it. The most prevalent among these legends is the tale of Laxman, the step-son of Karni Mata. One day while attempting to drink water from the Kapil Sarovar in Kolayat Tehsil, Laxman drowns in it. Grieved by his loss, Karni Mata prays ardently to Yama, the Hindu God of death, who first denies her request to bring her son back to life. However, moved by her sorrow and will, he gives in to her pleadings and reincarnates not just Laxman but all of Karni Mata’s male children as rats.

The construction of the Karni Mata Temple was concluded in the early 20th century by Maharaja Ganga Singh of Bikaner. The entire temple structure is raised in marble and its architecture evinces resemblance to the Mughal style. Adding to the charm of the attractive marble façade are solid silver doors that lead to an entry to the compound within. The panels of the silver doors depict the many legends of the Goddess. The idol of Karni Mata of Bikaner sits within the inner sanctum of the temple,a 75 cm tall statue holding a trident (trishul) in one hand, adorned by a crown and garlands. The idol of the Goddess is accompanied by that of her sisters on either side. The enhancement of the temple was further carried out in 1999, by Kundan Lal Verma, a Hyderabad-based Karni Jeweler. The marble carvings and silver gates were his contribution to the temple.

The regular affair at the Karni Mata temple involves the performance of Mangla-ki-Arti by and bhog offerings by Charan priests. Devotees visiting the temple also make various offerings to the Goddess and the kabbas (rats). These offering are generally categorized into two types – Dwar-bhent (attributed to priests and temple-workers) and Kalash-bhent (utilized for temple maintenance).

Apart from this, Karni Mata temple in Bikaner is known for the Karni Mata Fair which is a bi-annual event. The time of occurrence of these fairs is during the two Navratras –

1. Between March and April, from ChaitraShuklaEkam to ChaitraShuklaDashami

2. Between September and October, from AshwinShukla to AshwinShuklaDashami

The footfall during these fairs accounts in thousands. The Karni Mata Temple is open between 4 a.m. in the morning to 10 p.m. at night, everyday. There is no entry fee charged for admission within the temple.