Without seeing a close-up of the bugs, I'd guess they're aphids. Were any of your plants outside last summer? Last Summer I had a black bean aphid infestation in my outdoor plants that was the worst infestation I've ever had of bugs. To treat, it would be best to try to identify the insects. Take a photo with your cell phone of one of the bugs as close up as you can possibly get and still be in focus. Then after you take the picture, enlarge it so you can see the detail of the insect.

Where are you located?

Black bean aphids on clematis

Thrips

Deanna

Hi Deanna, thanks for your help! I'll try and find a closer photo; I think the bugs look more like thrips, but they are shiny - almost like a beetle. I've never really taken my plants outside apart from when repotting, but I've not done that recently. I'm in the UK.

Thank you for your concern!