Wildlife pond

Hi hope somene can help I put a small wildlife pond in around four years ago and I never seen any frog spawn in it all I see is snail and skaters and nothing else. I have some plants in the pond like frog bit and a small lily and an plant that' at the bottom of pond. Do I need anything else or will they just come one day
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https://www.woodlandtrust.org.uk/naturedetectives/blogs/nature-detectives-blog/2017/03/frog-facts/
Also near the pond are piles of cuttings, logs etc where they can hibernate
There were always frogs in the garden, but no spawn.
2 years ago I took spawn from another pond.