Firebugs (Pyrrhocoris apterus) [1] tend to aggregate in a sunny spot. Here they aggregate on a leaky garden hose connection, probably also for the moisture.

References
1 Nederlands SoortenregisterFirebugs (Pyrrhocoris apterus) [1] tend to aggregate in a sunny spot. Here they aggregate on a leaky garden hose connection, probably also for the moisture.
References
1 Nederlands Soortenregister