Lasius umbratus is a parasitic ant

Ant

Ants are social insects of the family Formicidae and, along with the related wasps and bees, belong to the order Hymenoptera. Ants evolved from wasp-like ancestors in the mid-Cretaceous period between 110 and 130 million years ago and diversified after the rise of flowering plants. More than...

. Queens

Queen ant

A queen ant is an adult, reproducing female ant in an ant colony; generally she will be the mother of all the other ants in that colony. Some female ants do not need to mate to produce offspring, reproducing through asexual parthenogenesis or cloning and all of those offspring will be female.Ant...

 find a Lasius niger

Black garden ant

The black garden ant is a formicine ant, the type species of the subgenus Lasius, found all over Europe and in some parts of North America and Asia. It is monogynous, meaning colonies have a single queen....

 worker ant, kill it to gain its scent and then are able to enter its nest. Once inside it finds and kills the queen. The worker ants will care for her larvae and slowly the colony will become one of Lasius umbratus. 'Umbratus' is Latin

Latin

Latin is an Italic language originally spoken in Latium and Ancient Rome. It, along with most European languages, is a descendant of the ancient Proto-Indo-European language. Although it is considered a dead language, a number of scholars and members of the Christian clergy speak it fluently, and...

 for the word 'ghost'.

They are sometimes confused with Lasius flavus (Yellow Meadow Ant) but unlike L. flavus they forage for food on the surface.