RHS - Royal Horticultural Society - "Small black flies around your houseplants? These could be fungus gnats – they breed in damp composts and can be a sign of overwatering. Water plants
![Fungus gnats 'biggest threat' to houseplants this summer - 'critical' way to prevent flies | Express.co.uk Fungus gnats 'biggest threat' to houseplants this summer - 'critical' way to prevent flies | Express.co.uk](https://cdn.images.express.co.uk/img/dynamic/13/590x/Fungus-gnats-biggest-threat-to-houseplants-this-summer-critical-way-to-prevent-flies-1634097.webp?r=1656686553509)
Fungus gnats 'biggest threat' to houseplants this summer - 'critical' way to prevent flies | Express.co.uk
![Greenhouse & Floriculture: Fungus Gnats and Shore Flies | Center for Agriculture, Food, and the Environment at UMass Amherst Greenhouse & Floriculture: Fungus Gnats and Shore Flies | Center for Agriculture, Food, and the Environment at UMass Amherst](https://ag.umass.edu/sites/ag.umass.edu/files/fact-sheets/images/fgsfstickycard.jpg)