I saw this red poppy with a bumblebee inside. I always thought that bees couldn’t see red and so never visited red flowers. This bee seems very busy inside this one. J Rushe, Co Clare
You are right: bees cannot see the colour red; their eyes don’t see colours at that end of the spectrum. But at the other end, the ultraviolet end, they see very well. There are well-defined markings in ultraviolet in poppies and this is what attracts bees in to seek for food. Interestingly, the same species of poppy in the Middle East does not have these UV markings, and there they are pollinated by beetles.

What is this bird that I saw perched on a grass stalk in Irishtown Nature Reserve in early June? There were loads of them there. S Woods, Dublin
This is a linnet, which has become quite uncommon because the intensification of our grasslands for cattle has greatly reduced the biodiversity of species found there. Linnets feed on a variety of seeds, especially thistles, and the use of herbicides and hedge removal has also contributed to their decline. Irishtown Nature Reserve is an excellent habitat for them and shows the value of such places.

The bush near where I live is covered in caterpillars, which are eating all the leaves. They seem to produce sheets of webs as well. This is a close-up of one caterpillar. C Birch, Dublin
This is the box tree caterpillar, which can decimate any species of Buxus – the species used in box hedging, which will grow into a sizeable bush if not clipped. This species of moth was first recorded here in 2017 and has spread rapidly since, to the detriment of box hedges. The cherry ermine moth has also been busy this summer, defoliating species of flowering cherries and covering them with webs too. Whole cherry trees can be affected, as was one in Dublin’s Herbert Park, among others.

There were two swarms of bees side by side hanging from a cherry tree in my garden here in Carrickmacross. They appeared at the same time. The big one is 12-15 inches long. Does this mean that two queens left the hive at the same time? They were recovered by a beekeeper. Fred Fitzsimons, Co Monaghan
The old resident queen who has overwintered in the hive will leave with a swarm if the hive gets too full, leaving the about-to-hatch new queens to fight to the death for the queenship of the vacated hive. There is only ever one resident queen bee in a hive. The swarm, with the queen inside, can cluster on a convenient tree waiting for its scouts to return with information of a suitable place to take up future residence. Two swarms with two different queens from two different hives coincidentally used this halting site at the same time. The weather was really good in May and bee numbers increased enormously.

Coots are breeding on the pond in UCD, the most recent one beside the law school. They have at least two young. M Bell, Co Wicklow
Build it (or in this case, excavate it) and they will come. This – the most recent UCD lake – was constructed in 2013, replacing an existing car park, and is a haven for biodiversity. Coots prefer shallow water with lots of bottom vegetation for feeding, with reed beds and other waterside plants for nesting cover. The male brings the nesting material (dead water plants) and the female arranges it and lays the eggs.
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