this is my image of what would happen if two Sentret tried to intimidate eachother...

i just had to add DeidaraNarutoClan's comment into the description because its practically what i was thinking when i made this:
In order to gain territory, the sentret must make themselves seem larger than another sentret so they won't be overpowered. The larger belly they have, the more intimidating they seem... however, it can end up as badly as a trainer tipping over a miltank or a squirtle falling on its back