16. Mount of of Lord Ganesha

The most commonly known and spoken about vehicle of Lord Ganesha is the mouse or shrew (musak, mooshaka). It has been referred to as Mūsakavāhana (meaning the mouse mount) and Ākhuketana (rat-banner) in the Ganesha Sahasranama.

The vehicle is also called the steer, Charioteer, vahana or Mount or carrier. 

Legendary stories gathered from various scriptures describe various forms and incarnations of Ganesha. The Mount in different forms and incarnations varies as too.

The Mudgala Purana describes eight  incarnations of Ganesha. The first incarnation as Vikata has peacock as his vehicle. The second incarnation - has as it vechile.

The Ganesha Purana describes four incarnations of Ganesha. The first incarnation, Mohotkata has lion as its Mount. The second incarnation as Mayūreśvara has a peacock, the third incarnation Dhumraketu has a horse, and Gajanana has a rat.

Ganesha Seated on Lion

1.Mahotkata - Lion
2. Mayureshvar - Pecock
3. Gajânana - Mouse
4.Dhûmraketu -  Blue Horse

The Jain scriptures with depictions of Ganesha variously reveal mouse, elephant, tortoise, ram, or peacock as his Mount.

  

What does the mouse signify?
The mouse as Ganesha's charioteer has been interpreted variously. The Sanskrit word musaka means one who steals or robs.
1. Ganesha mounts the mouse means He subdues destructive tendencies such as stealing, hoarding, desire, ego of the mouse. In other words, Ganesha subdues the obstacles (hence the name Vignaharta) created by various demonic forces.
2. The rat represents the raja aspect of existence. The association of rat with Ganesha signifies that the God has the ability to control the destructive fsorces.

3. Rats known to breed very fast. Thus in symbolic context, rats represent fertility or the ability to multiply. However, they are relentless and cause damage to grain, etc creating havoc. In this context they represent greed and avarice.  When Ganesha mounts the rat, its adverse aspects are subdued. It is then associated with good acumen, presence of mind, growth and prosperity.

Shrew, mouse or rat - which of them is Ganesha's mount ?  

Sacred text mention Mooshika as the vahana of Lord Ganesha. However, weather the Mooshika refers to mouse, or a rat (or bandicoot) is unclear. It remains a matter of scholarly debate.

Some scholars consider shrew as the vehicle of Lord Ganesha. As such shrew is considered sacred.

At times, Shrews invade human dwellings. However, they are never killed. The Shrews are caught in live traps and released in wild.

It us customary to offer some grains to Shrew as a part of ritualtistic worship of Lord Ganesha.

Difference between rat and mouse

Rat and mouse are biologically different species (though related by their descend).
mice (Mus musculus) and Norway or black rats (Rattus norvegicus and Rattus rattus)

1. Mouse is smaller than rat.
2. A rat has a thick, scaly and heavy tail whereas mouse has a small tail.
3. Mouse has larger ears in proportion to their head which appear smaller. Rats have small ears and large head.
A rat has large feet.
4. Mouse and rats differ genetically.
5. They exhibit behavioural differences too. Rats are known to be cautious and intelligent creatures. They are curious and donot approach new objects readily. On the other hand, mouse are investigative by nature and easy approach new objects. Thus a mouse is easily trapped than a rat.
6. Mouse has more longevity than rat. A rat may live for three to four years, whereas mouse can live up to five years.
7. Mouse is dark brownish. Rat is greyish with white abdomen.

If mouse and rat are kept together they may turn rebellious. A rat may even kill mouse and eat it!