Even if you haven’t got room for a pond, any small container of water will encourage important wildlife. Include an oxygenated plant like a water lettuce or the 100’s of lovely water plants available to grow inside it.
I have a plant called the Egyptian Plant (or that is the name my friend gave it, when she gave me a cutting) and it grows in water as well as in soil and one of my cats eats it up hungrily. They all pounce on lemon grass also and gobble up the leaves so fast, it is impossible to keep it growing near them. They also drink up water in which water plants grow which is worrying. But nothing seems to have happened to them for many years.