What's this bush ? Ants ! *pictures*

[runsmidgeOMG]

Can anyone identify this bush? It's got ants at the end of all its branches. Am I ok to just leave them ?

Your problem there isn't the ants- it's that the ants are busy farming aphids! And the aphids can be a problem. The bush looks happy enough though. I've no clue what it is, unhelpfully...

a type of viburnum?

Ooh total gardening novice here
What are aphids ? Baby ants ?

No. Greenfly - the pp thinks the ants are taking them to eat.

No wowfudge, the ant don't eat the aphids.
The aphids are tiny insects which suck the sweet sap of plants, they can weaken a plant and stop it from growing. They exude a sticky sweet substance of their own, honeydew. This can sometimes go mouldy and cause a black mound on the plant, or it can cause the leaves and the ground nearby (or the shelf if indoors) to get very sticky. The ants like the honeydew, so they look after little colonies of aphids and collect the honeydew. I think (not certain) they sometimes move the aphids from place to place to set up better colonies.

I stand corrected - thanks @MessySurfaces.

If you put a dish of sugar water at the foot of the bush, the ants will stop farming the aphids, and the ladybirds etc will be able to come and eat them.

Wow insects are complex !!! But very interesting :)