What are springtails?
Springtails aren't actually insects - they're insect-like creatures known as 'Collembolans' which feed on decaying organic material and mold, meaning they're drawn to damp conditions. Overwatered plants are a particularly inviting environment for Springtails, so if you'd like to keep them away then be sure to allow your plant to dry out between waterings (if it is a plant type that is okay with this).
They can be a number of colors, but are typically pale/white, tiny and wingless. They’re often found in running around on top of the soil or in the tray of the plant.
Are Springtails bad for your plants?
You don't need to worry about Springtails causing harm to your plant. They only like eating dead material, so while they may chew on old roots or leaves, they won't damage your living plant. Therefore, if they don't bother you then it's perfectly fine to leave them be. They'll even help to clear the soil of debris for you! A simple way to deter them though is to just remove any decaying material yourself, as this eliminates their food source.
As they're drawn to moisture, you can also try reducing the humidity around your plants and ensuring the soil never stays too wet for prolonged periods of time (just make sure your plants still get their care needs met).
You also don't need to worry about them causing damage to anything else in your home. Although they can technically be classed as a pest in that some people consider them a nuisance, they don't bite nor do they eat clothes or furniture etc. They tend to just hang out in the soil and keep to themselves, and once their supply of dead material to eat runs out they'll move on to live somewhere else.