I was standing at my window looking out at the gathering dusk when a small mammal popped out of the shrubs and darted down the rock wall, and across our paved verandah. Antechinus!  I have lived in this house on a small bush block for 15 years and this is my second sighting of this little animal. The antechinus is a carnivorous marsupial, in the same family as the Tassie Devil, quolls and the rat-sized Brush-tailed Phascogale.

The last time I saw our resident antechinus was also at dusk, as he or she drank deeply from a bird bath that is set on the ground. But how do I know they are here all the time? Their scats!

Antechinus scats or droppings are the key to identifying whether your scuttling brown mammals are rats or native marsupials. In most bush houses and gardens around here we have a mix of introduced Black Rats, Agile Antechinus and possibly native Bush Rats.

A beautiful little critter, note the notched ears. Pic by Mel Williams

To tell the difference between a Black Rat and a native Bush Rat – look at the tail. The Black Rat’s tail is twice as long as its body and is nearly naked, almost segmented like a very skinny earthworm. The Bush Rat’s tail is shorter than its body and quite furry. Warning: the cuteness factor does not help you distinguish between these two species – some Black Rats are simply adorable with their fine whiskers, soulful eyes and little white chests. We had a visitor from Sydney taking pics of a Black Rat clambering around on our washing up – only later did I realise it was not an adorable Antechinus or native Bush Rat! Oops.

Black rat: left, Bush rat on the right: credit Taronga Zoo

Scat identification is a fun hobby – it is all about textures, and knowing a bit about the animal’s diet. Black Rats and Bush Rats are omnivorous – indeed Black Rats will eat nearly anything. Their scats are hard, cylindrical pellets that are pretty uniform in size and shape, often with a little point at one end. When you break them open they are compacted and simply break in half. Mouse scats are similar in texture, just smaller.

Agile Antechinus, on the other hand are insectivores – they eat mostly insects, with hard chitinous exoskeletons. The antechinus has long pointed jaws full of many sharp teeth which chew their insect prey up very finely. So when you pick up an antechinus scat and crumble it slightly between thumb and forefinger the whole thing breaks up into a zillion tiny brown fragments which may have a bit of iridescence. In scat parlance, they are known as ‘friable’.

Antechinus scats may be cylinders with rough broken off ends, or even curled “Mr Whippy” style scats. If the scats are friable and full of insect fragments but tiny and in great numbers – you could be looking at bat scats, as microbats also have an insect diet.

One would think that being able to identify the scats means I can confidently say whether it is Black Rats or Antechinus keeping us up at night in the roof. At our house, it seems these two species coexist – and both scats may be found under our roof.

The Antechinus leaves more scats in the shed and across the woodpile – seeming to drop them freely as they scamper about, whereas the Black Rats seems to save their scats for depositing in their creepy lairs, in secret dark places such as under tin sheets in the garden,  and notoriously in car engines!

Another way to tell these two animal groups apart is their two very distinctive gaits. Rodents, whether they are native or introduced, run in a smooth continuous motion, kind of like a horse in a gallop. Antechinus move in a very different way, it is staccato and super fast, a kind of coordinated hopping gait that moves across the ground or log like a horizontal hop. The only other animals I have seen move like this are possums and bandicoots – also marsupials.

The Agile Antechinus is one of the most common animals in the Wombat Forest, and the star of the Wombat Forest camera trapping program run by Wombat Forestcare and the VNPA. If you live in the drier parts of the Hepburn Shire, such as Yandoit or Clydesdale you would have the Agile’s Antechinus’ larger fluffier cousin, the very pretty Yellow-footed Antechinus.