The best replacement for rat is mouse.

The best alternatives to rat are rated as following:
★★★★★  mouse
★★  hamster
★★  guinea pig
★★  mouse droppings
★★  cat
★  snake
★  possum
★  mice
★  squirrel droppings
★  rabbit
★  mouse pet
★  squirrel
★  ferret
★  gerbil
★  ocd
★  big muff
★  mouse poop
  guinea pig as pet
  frog
  pods
  rat 2
  turbo rat
  hedgehog
  spider
  robber
  ferret pet
  esee
  mice droppings
  rat
  tube screamer
  piranha
  kangaroo mouse
  mouse picture
  roof rat
  mouse difference
  ds-1
  ds1
  gopher
  female rat
  mouse pictures
  muskrat
  dragon
  hoarder

Your alternative for rat is not listed? Suggest!
Speaking about rat, one probably shouldn't forget about whiskers.

Other search terms related to rat and their ratings are:
★★★★★ whiskers
human ear on back
You have in mind a companion for rat and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of rat in all years. Click on graph for more.
rat
mouse
hamster