Goldfinch Invasion

Earlier in the year we noticed that our neighbour had goldfinches on her feeder and we didn't so we asked her what to feed them. Anyway we set up 3 hanging feeders on a feeder station and were delighted to see goldfinches appear. We put niger seed and sunflower hearts in the feeders. I was particularly pleased last week to see four adults and two juveniles all together, but yesterday evening at around 5.30pm I counted ten adult goldfinches all together at the three feeders. There was a bit of squabbling going on, but it was a great sight.   Do goldfinches tend to flock together at certain times of the year?